Biomedical subjects

M Bojić

Publications and source records attributed to M Bojić.

At least 37 records · Page 2Linked to original sources

PubMed1999

Low incidence of cardiac abnormalities in treated trichinosis: a prospective study of 62 patients from a single-source outbreak.

PURPOSE: The reported incidence of cardiac involvement in trichinosis is highly variable, ranging from 21% to 75%. This study sought to determine the incidence and type of cardiac lesions in trichinosis using serial echocardiographic examinations. SUBJECTS AND METHODS: Sixty-two consecutive patients admitted to the Banja Luka Medical Center during an outbreak of trichinosis (November to December 1996) were included in the study. Diagnosis was made by typical clinical presentation, positive epidemiologic history, serologic testing, and the detection of Trichinella larvae in contaminated meat. All patients underwent serial electrocardiograms and two-dimensional and Doppler echocardiographic examinations within 20 days after the onset of symptoms. Repeated echocardiographic examinations were performed weekly during the hospital stay in all patients with electrocardiographic abnormalities or an abnormal initial echocardiogram. RESULTS: Cardiac involvement (electrocardiographic and/or echocardiographic changes) was detected in 8 (13%) of the 62 patients. Nonspecific transient electrocardiographic ST-T changes were found in 6 patients (10%); 1 patient had frequent premature ventricular complexes. Echocardiographic examinations revealed pericardial effusions in 6 patients (10%), 5 of whom had minimal effusions without impairment of global and regional left ventricular systolic function. One patient had hypokinesis of the interventricular septum with a small pericardial effusion, both of which resolved within 2 weeks. Only 2 of the patients with electrocardiographic abnormalities lacked echocardiographic evidence of cardiac involvement. At 6-month follow-up, none of the patients had electrocardiographic or echocardiographic abnormalities. CONCLUSIONS: The incidence of cardiac involvement in trichinosis appears to be lower than previously reported. Pericardial effusion is the most common manifestation of cardiac involvement, and nonspecific transient electrocardiographic changes, traditionally ascribed to myocarditis, more frequently reflect pericarditis.

Adult↗

PubMed1999

Immediate reoperation for perioperative stroke after 2250 carotid endarterectomies: differences between intraoperative and early postoperative stroke.

PURPOSE: After carotid endarterectomy, intraoperative findings and outcome of immediate reoperation of patients who had an intraoperative stroke were compared with those of patients who had an early postoperative stroke. METHODS: We retrospectively analyzed 2250 carotid endarterectomies performed between 1980 and 1997. Intraoperative stroke (group A) was detected after 41 of the 2250 operations (1.8%), whereas early postoperative stroke (group B) developed after 18 of the 2250 operations (0.8%). Patients from both groups were reoperated on within 1 hour after neurological examination. RESULTS: Positive intraoperative findings that could be corrected during immediate reoperation were: (1) thrombotic occlusion of the carotid artery that was operated on caused by technical error, which was found in nine of 41 patients (22%) in group A and in 11 of 18 patients (61%) in group B (P =.009); (2) mural thrombus caused by technical error without occlusion, which was detected in seven of 41 patients (17%) in group A and in two of 18 patients (11%) in group B (P >.05); and (3) technical error without a thrombus, which was found in eight of 41 patients (20%) in group A and in three of 18 patients (17%) in group B (P >.05). A patent carotid artery was found in 17 of 41 patients (42%) in group A and in two of 18 patients (11%) in group B (P =.046). Twenty of the 41 patients (49%) in group A died, and four of 18 patients (22%) in group B died (P > 0.05). Major neurological deficit remained in nine of 41 patients (22%) in group A and four of 18 patients (22%) in group B (P > 0.05). Total recovery occurred in seven of 41 patients (17%) in group A and in eight of 18 patients (45%) in group B (P = 0.058). CONCLUSION: Carotid artery thrombosis during immediate reoperation was more frequent in patients who had an early postoperative stroke than in patients who had an intraoperative stroke. It appears that patients who had an intraoperative stroke have a higher incidence of uncorrectable lesions.

Carotid Stenosis↗

PubMed1999

Association of Killip class on admission and left ventricular dilatation after myocardial infarction: a closer look into an old clinical classification.

BACKGROUND: Early identification of patients in whom left ventricular dilatation is likely to occur may have important therapeutic implications. Thus the purpose of this study was to evaluate the relation between Killip class on admission and subsequent left ventricular dilatation after acute myocardial infarction. METHODS AND RESULTS: We serially evaluated 129 consecutive patients by two-dimensional and Doppler echocardiography on days 1, 2, 3, and 7, at 3 and 6 weeks, and at 3, 6, and 12 months after infarction. Killip class on admission >1 was found in 29 of 129 (22.5%) patients, and they had significantly higher end-systolic and end-diastolic volume indexes and wall motion score index from day 1 onward compared with patients with Killip class 1, whereas ejection fraction was lower during the follow-up period in these patients. Patients with Killip class >1 showed the progressive increase of end-diastolic (68.2 +/- 2.99 to 88.0 +/- 7.55 ml/m2, p = 0.001) and end-systolic volume indexes (43.9 +/- 2.67 to 56.3 +/- 6. 18 ml/m2, p = 0.004) during the follow-up period, whereas ejection fraction and wall motion score index remained unchanged. In patients with Killip class 1, end-systolic volume index did not change (30.8 +/- 1.06 to 33.8 +/- 2.15 ml/m2, p = 0.064), ejection fraction increased (49.3% +/- 0.99% to 51.8% +/- 1.17%, p = 0.027), and wall motion score index decreased (1.50 +/- 0.03 to 1.35 +/- 0.04, p < 0. 001). End-systolic volume index was the major independent correlate of Killip class, followed by history of diabetes and peak creatine kinase level. No association was found between Doppler indexes of diastolic filling and Killip class on admission. CONCLUSIONS: Killip class >1 on admission is associated with both acute and long-term left ventricular dilatation. On the other hand, Killip class 1 is associated with favorable left ventricular functional indices, and it appears that left ventricular function in these patients may improve over time. Initial end-systolic volume index but not ejection fraction is the major correlate of Killip class.

Coronary Angiography↗

PubMed1999

Doppler-based diagnosis of restenosis after femoropopliteal percutaneous transluminal angioplasty: sensitivity and specificity of the ankle/brachial pressure index versus changes in absolute pressure values.

The aim of this study was to investigate the sensitivity and specificity of changes of the ankle/brachial pressure index (ABI) and changes in absolute ankle pressure values to detect restenosis in patients who underwent femoropopliteal percutaneous transluminal angioplasty (PTA). In total, 171 patients were followed up prospectively for 12 months; sensitivity and specificity of Doppler-based diagnosis were calculated with duplex scanning as the gold standard. The criteria for restenosis were: (1) a loss of 50% of the ABI increase or (2) loss of 50% of the absolute ankle systolic pressure, gained by PTA. For both criteria, different cut-off points (minimum increase of ABI or ankle pressure gained by PTA) were evaluated. The overall sensitivity and specificity of the ABI criterion was 67% and 80%, respectively. The introduction of cut-off points (the minimum ABI increase gained by PTA), ranging between > or = 0.13 and > or = 0.35, did not markedly improve the results. The overall sensitivity and specificity of the absolute ankle pressure criterion again was poor (59% and 81%). With the introduction of cut-off points (the minimum increase of absolute ankle pressure gained by PTA) ranging between > or = 15 mm Hg and > or = 20 mm Hg, the sensitivity and specificity of the criterion improved to acceptable 92% and 96%, respectively. It is concluded, that in the long-term follow-up of PTA patients, the "loss of 50% ankle pressure" criterion will detect restenosis with reasonable accuracy in those patients, in whom an increase in systolic ankle pressure > or = 20 mm Hg is warranted.

Aged↗

PubMed1999

Interaction between L-arginine: no system and cyclooxygenase metabolic products of arachidonic acid in coronary autoregulation.

Coronary autoregulation (CA) is the intrinsic ability of the heart to maintain its nutritive blood supply constant over a wide range of perfusion pressure. This phenomenon is regulated through several control mechanisms, while metabolic and myogenic control mechanism have dominant effects. In last few years, endothelial control mechanism, which is part of metabolic control, was intensive investigated. Dominant topic of endothelial-investigation was bioregulatory L-arginine: NO system, with his effective product--nitric oxide (NO). On the other hand, cyclooxygenase metabolic pathway products of arachidonic acid plays an important role in the control of vasomotor tone of coronary arteries. For this purpose, the aim of our study was to evaluate role of L-arginine: NO system, cyclooxygenase metabolites of arachidonic acid, as well as, their interactions in the control of CA of the isolated rat heart.. In our study rat hearts autoregulate CF between 50 and 90 cm H2O of CPP. Basal release (at 60 cm H2O) of NO (as nitrite), cAMP, cGMP and HX+X (i.e. adenosine) amounted to 2.85+/-0.25 nmol/min/g wt, 29.45+/-2.22 pmol/min/g wt, 0.43+/-0.08 pmol/min/g wt and 37.50+/-2.89 nmol/min/g wt respectively. Release of NO, cAMP and cGMP were strictly parallel with CPP-CF curve, while release of adenosine (i.e. HX + X) was an inverse function of perfusion pressure. Inhibition of NOS (L-NAME, 30 micromol/l) significantly widened autoregulatory range (40-100 cm H2O), with significant reduction in CF and NO- and cGMP release, while release of cAMP was completely reversed in the presence of L-NAME. However, inhibition of cyclooxygenase didn't influence autoregulatory range, with similar changes of NO- and cAMP-release and completely inversed values of released adenosine. When L-NAME an indomethacin (an nonspecific COX-inhibitor), 3 micromol/l where added together, they exhibit interactions between these two enzymatic systems. Namely, when L-NAME was added first, indomethacin didn't influence hemodynamic effects of NOS-inhibitor. On the other hand, when COX-inhibitor was added first, L-NAME widened autoregulatory range in small manner as after control autoregulatory experiments (40-90 cm H2O). All hemodynamic changes were followed with similar changes in NO-release, what suggest that exist interaction between L-arginine: NO system and COX-metabolites in the regulation of coronary autoregulation.

Animals↗

PubMed1998

Myocardial tissue characterization after acute myocardial infarction with wavelet image decomposition: a novel approach for the detection of myocardial viability in the early postinfarction period.

BACKGROUND: Only a few texture measures can be used for texture characterization of infarcted myocardium and detection of reperfused myocardium early after infarction. This study was conducted to establish the relationship between texture properties of infarcted myocardium and infarct-related artery patency by quantitative computer analysis of 2-dimensional echocardiographic images with the wavelet-based method for texture characterization, evaluate the relationship between texture properties and myocardial viability, and correlate histopathologic changes after experimental infarction with the texture measures. METHODS AND RESULTS: We analyzed 2-dimensional transthoracic echocardiographic images in 18 patients at different time points after infarction using the wavelet transform method. Regional wall motion of infarcted segments was analyzed on a follow-up echocardiographic study obtained 6 months after infarction. To verify the accuracy of the proposed texture measure and energy difference cutoff value, we prospectively evaluated another group of 19 patients. In addition, histopathologic changes in 9 dogs with experimental infarction were correlated with the texture measures. Sensitivity, specificity, and accuracy of the wavelet method for detection of reperfusion in the study group were 73%, 86%, and 78%, respectively, on day 2; 91%, 86%, and 89%, at 1 week; and 100%, 100%, and 100% at 3 weeks. Among 9 patients with improvement in regional wall motion on a follow-up study, 7 on day 2, 8 at 1 week, and 9 at 3 weeks were classified into the reperfused group by the wavelet method. Histopathologic features associated with the classification of reperfusion by the wavelet method were infarct transmurality (P=0.024) and degree of necrosis (P=0.028). CONCLUSIONS: Our clinical and experimental data suggest that the wavelet method can be used to differentiate between viable myocardium with recovery potential and definite myocardial necrosis in the early postinfarction period.

Animals↗

PubMed1998

Acute hemodynamic effects of metoprolol +/- nitroglycerin in patients with biopsy-proven lymphocytic myocarditis.

We evaluated acute hemodynamic effects of metoprolol +/- nitroglycerin in 11 patients with left ventricular dysfunction and biopsy-proven lymphocytic myocarditis. Acute administration of metoprolol improved ejection phase indexes, probably through the prolongation of diastole; the addition of a vasodilator further enhanced these effects by improving arterial elastance.

Adrenergic beta-Antagonists↗

PubMed1998

Partial left ventriculectomy for idiopathic dilated cardiomyopathy: early results and six-month follow-up.

BACKGROUND: Recent reports show that partial left ventriculectomy improves hemodynamic and functional status in patients with dilated cardiomyopathy. This study sought to determine the effects of partial left ventriculectomy on clinical outcome and left ventricular function during 6-month follow-up. METHODS: Twenty-two patients underwent partial left ventriculectomy. Mitral valve repair was performed whenever possible, otherwise the valve was replaced. Hemodynamic and functional data were obtained at baseline, as well as 2 weeks and 6 months postoperatively. RESULTS: Overall, 7 of 22 patients died; there were three early and four late deaths. One-year survival was 68%+/-10%. Ejection fraction increased from 23.9%+/-6.8% before the operation to 40.7%+/-12.5% at 2 weeks and to 36.8%+/-7.7% at 6 months (p<0.001, for both). The cardiac index before the operation, at 2 weeks, and at 6 months was 2.3+/-0.8, 2.9+/-0.6, and 3.4+/-1.0 L/m2 per minute, respectively (p = 0.035, and p = 0.009, compared with baseline). The increase in ejection fraction 2 weeks postoperatively was less in patients with left circumflex artery dominance (10.9%+/-3.2% compared with 19.9%+/-10.7%, respectively, p = 0.017). At 6-month follow up, all surviving patients except one improved New York Heart Association functional class when compared with preoperative status (from 3.8+/-0.4 to 1.4+/-0.6, p = 0.0002). CONCLUSIONS: Early hemodynamic improvement after partial left ventriculectomy was maintained during midterm follow-up.

Cardiac Surgical Procedures↗

PubMed1998

Effects of partial left ventriculectomy on left ventricular performance in patients with nonischemic dilated cardiomyopathy.

OBJECTIVES: This study sought to assess the effects of partial left ventriculectomy (PLV) on left ventricular (LV) performance in a series of consecutive patients with nonischemic dilated cardiomyopathy. BACKGROUND: Reduction of LV systolic function in patients with heart failure is associated with an increase of LV volume and alteration of its shape. Recently, PLV, a novel surgical procedure, was proposed as a treatment option to alter this process in patients with dilated cardiomyopathy. METHODS: We studied 19 patients with severely symptomatic nonischemic dilated cardiomyopathy, before and 13+/-3 days after surgery, and 12 controls. Single-plane left ventriculography with simultaneous measurements of femoral artery pressure was performed during right heart pacing. RESULTS: The LV end-diastolic and end-systolic volume indexes decreased after PLV (from 169 to 102 ml/m2, and from 127 to 60 ml/m2, respectively, p < 0.0001 for both). Despite a decrease in LV mass index (from 162 to 137 g/m2, p < 0.0001), there was a significant decrease in LV circumferential end-systolic and end-diastolic stresses (from 277 to 159 g/cm2, p < 0.0001 and from 79 to 39 g/cm2, p = 0.0014, respectively). Ejection fraction improved (from 24% to 41%, p < 0.0001); the stroke work index remained unchanged. CONCLUSIONS: The PLV improves LV performance by a dramatic reduction of ventricular end-systolic and end-diastolic stresses. Further studies are needed to assess whether this effect is sustained during long-term follow-up and to define the role of PLV in the treatment of patients with dilated cardiomyopathy.

Adult↗

PubMed1998

Combined carotid and coronary artery surgery: what have we learned after 15 years?

UNLABELLED: Optimal surgical strategy in patients with concomitant coronary and carotid artery disease is debatable. We have analysed 15-years of experience (January 1981-August 1996) with 195 consecutive patients in whom we have used two different surgical approaches. Group A consisted of 48 patients who underwent a single-stage surgical procedure, and group B (147 patents) underwent a two-stage procedure, either as carotid endarterectomy followed by coronary artery bypass surgery (group B1, 97 patients), or as coronary artery bypass surgery followed by carotid endarterectomy (group B2, 50 patients). Overall, there were 40 (20.5%) patients with left main coronary artery disease, 49 (25.1%) with poor left ventricular function, 128 (65.6%) with previous myocardial infarction, 134 (68.7%) were in New York Health Authority (NYHA) functional class III or IV, and bilateral carotid involvement was present in 57 patients (29.2%). Unstable angina was more frequent in groups A and B2 (P < 0.0001), NYHA class III-IV was more frequent in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction (EF) was more frequent in groups A and B2 (P < 0.0001 for both), bilateral carotid stenosis in groups A and B1 (P = 0.02 and P = 0.0001, respectively) and ulcerated plaque in group B1 (versus A, P = 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. RESULTS: Early mortality for the entire group was 4.6% (9/195-6.2% in group A, 6.2% in group B1 and 0% in group B2, respectively P > 0.05). Serious morbidity occurred in 7.3% of patients (14/195-8.3% in group A, 7.2% in group B1 and 6% in group B, respectively P > 0.05). Univariate analysis revealed only bilateral carotid stenosis as a predictor of outcome (P = 0.04). Follow-up was completed for 156 patients (80.0%) and averaged 84.1 +/- 13.3 months (range 1-180 months). Kaplan-Meier survival estimate for the entire group was 81% and event-free survival was 76% at 5 years. Actuarial and event-free survivals were similar for all groups. Early and late outcome in these patients were influenced more by their preoperative clinical status than by the surgical strategy itself. It is therefore concluded that surgical approach should be individualized for the majority of patients.

Actuarial Analysis↗

PubMed1998

Predictors of left ventricular thrombus formation and disappearance after anterior wall myocardial infarction.

AIMS: This study sought to determine predictors of left ventricular thrombus formation and resolution after acute anterior wall myocardial infarction. METHODS AND RESULTS: We have analysed clinical, echocardiographic and angiographic data in 53 consecutive patients with anterior myocardial infarction. Two-dimensional and Doppler echocardiographic examinations were performed on days 1, 2, 3 and 7, after 3 and 6 weeks, and 3, 6, and 12 months following infarction. Coronary angiography was performed in 44 patients before hospital discharge. Left ventricular thrombus was detected in 30/53 patients (29/30 in the first week after infarction). Univariate analysis showed that left ventricular thrombus formation was associated with a higher initial end-systolic volume index (beta = 0.04, P = 0.001), and end-diastolic volume index (beta = 0.03, P = 0.03), a larger infarct perimeter (beta = 0.02, P = 0.01), a lower initial ejection fraction (beta = 0.06, P =0.001), a higher initial wall motion score index (beta = 1.75, P = 0.023), a higher peak creatine kinase level (beta = 3.90, P = 0.01), Killip class >1 (beta = 1.11, P = 0.003), infarct expansion (beta = 0.78, P = 0.04), occluded infarct-related artery (beta = -0.87, P = 0.04) and non-thrombolytic therapy (beta = -0.76, P = 0.047). According to the Cox proportional regression model, independent predictors of thrombus formation after anterior myocardial infarction were high end-systolic volume index (beta = 0.06, P = 0.001) and high peak creatine kinase level (beta = 5.17, P = 0.046). Thrombus disappeared in 11/30 (36.7%) patients during one-year echocardiographic follow-up. The only independent predictor of thrombus disappearance after acute myocardial infarction was the absence of apical dyskinesis 6 weeks after infarction (beta = -1.53, P = 0.045). CONCLUSIONS: Our data demonstrate that the best predictor of left ventricular thrombus formation after acute anterior myocardial infarction is a high initial end-systolic volume. Thrombus resolution is more likely to occur in patients without apical dyskinesis at the end of the healing phase of infarction.

Anticoagulants↗

PubMed1997

Detection of significant residual stenosis of the infarct-related artery after thrombolysis by high-dose dipyridamole echocardiography test: is it detected often enough?

BACKGROUND AND HYPOTHESIS: It has been reported that high-dose dipyridamole echocardiography test (DET) can be successfully used for the detection of critical residual stenosis of the infarct-related artery (IRA). However, we have recently noticed low sensitivity of DET for the detection of residual IRA stenosis in patients with single-vessel disease. This study sought to determine the value of DET for the detection of significant residual stenosis of the IRA after thrombolysis. METHODS: Dipyridamole echocardiography test was performed in 55 consecutive patients after a first acute myocardial infarction before hospital discharge. All patients underwent coronary angiography 23 +/- 6 days after infarction. RESULTS: Nine of 19 patients with positive DET revealed new adjacent asynergy and all of the patients had patient and significantly stenotic IRA. Sensitivity and specificity of DET in identifying significant residual stenosis of the IRA were 24 and 100%, respectively. Among 49 patients with significantly stenotic of occluded IRA, 40 patients without adjacent asynergy during DET had higher baseline wall motion score index (WMSI) compared with 9 patients who revealed adjacent asynergy during DET (1.45 +/- 0.30 vs. 1.24 +/- 0.18; p < 0.05). When all patients with positive DET (adjacent or remote asynergy) were compared with those with negative DET, no difference in baseline WMSI was found (1.37 +/- 0.24 vs. 1.44 +/- 0.24; p > 0.05). CONCLUSIONS: Our data indicate that sensitivity of DET in detecting significant residual stenosis of the IRA after thrombolysis is low. It seems that the extent of myocardial infarction affects the ability of DET to detect adjacent, but not remote asynergy.

Aged↗

PubMed1997

Cardiac events after combined surgery for coronary and carotid artery disease.

OBJECTIVE: To evaluate serious cardiac events after combined (either single or two stage) coronary artery surgery (CAS) and carotid endarterectomy (CEA) for concomitant coronary and carotid artery disease. METHODS: We have analyzed our 15 year experience (January 1981-September 1996) with 201 consecutive patients operated on using both approaches. Group A consisted of 48 patients with the single-stage procedure, while in group B (153 patients), two stage procedure was carried out, either as carotid endarterectomy (CEA), followed by coronary artery bypass surgery (CAS) (group B1- 103 patients), or as CAS followed by CEA (group B2- 50 patients). Five patients from B1 group died after the CEA procedure, but were included, despite the fact they never reached the second stage. Left main coronary artery disease was found in 41 patients (20.4%), poor left ventricular function in 49 (24.4%) previous MI in 133 (66.2%), while 136 (67.7%) were in NYHA functional class III or IV. Bilateral carotid involvement was present in 61 patients (30.3%). Unstable angina was more prevalent in groups A and B2 (P < 0.0001). NYHA class III/IV in group A (versus B1, P = 0.001 and versus B2, P = 0.02), low ejection fraction in groups A and B2 (P < 0.0001), bilateral carotid stenosis in group B1 (versus A, P = 0.003 and versus B2, P < 0.0001), and ulcerated plaque in group B1 (P < 0.0001). These differences dictated the surgical strategy, which resulted in different protocols for clinical and operative management. RESULTS: Early mortality for the entire group was 5.5% (11/201) 6.2% in group A, 7.8% in group B1 and 0% in group B2, respectively; (P > 0.05). Serious morbidity occurred in 7.5% of patients (8.3% in group A, 7.8% in group B1 and 6% in group B2, respectively; P > 0.05). Univariate analysis revealed only bilateral carotid stenosis to influence early outcome (P = 0.04). CONCLUSION: Patients with concomitant coronary and carotid artery disease have relatively good immediate operative results, providing all existing lesions are corrected. Despite it did not reach the statistical significance, cardiac events were less frequent in groups A and B2 indicating possible protective effect of prior CAS in patients with concomitant disease.

Aged↗

PubMed1997

The effects of levcromakalim and pinacidil on the human internal mammary artery.

The present study was undertaken to examine the effects of pinacidil and levcromakalim, two potassium, channel openers, on human internal mammary artery (HIMA) obtained from patients undergoing coronary artery bypass surgery, and to clarify the contribution of different K+ channel subtypes in pinacidil and levcromakalim action in this blood vessel. Pinacidil and levcromakalim induced a concentration-dependent relaxation of the precontracted arterial segments (pEC50 = 5.77 +/- 0.05 and 6.89 +/- 0.03, respectively), 4-Aminopyridine (3 mM), a non-selective blocker of K+ channels, induced significant shifts to the right of the concentration-response curves for pinacidil and levcromakalim. Tetraethylammonium (6 mM), charybdotoxin (0.4 microM) and apamin (0.1 microM), blockers of Ca(2+)-sensitive K+ channels, had no effect on the pinacidil- and levcromakalim-evoked relaxation. Glibenclamide (0.1-10 microM), a selective blocker of adenosine triphosphate (ATP)-sensitive K+ channels, competitively antagonized the response to levcromakalim (pKB = 7.92 +/- 0.07). In contrast, glibenclamide, in significantly higher concentrations (3-30 microM), non-competitively antagonized the response to pinacidil. High concentrations of pinacidil (> 10 microM) relaxed arterial rings bathed by a medium containing 100 mM K+ with maximum response 83 +/- 6%. Under the same conditions, the maximum levcromakalim-induced relaxation on HIMA was almost abolished (15 +/- 2%). It is concluded that pinacidil and levcromakalim do not relax the HIMA through the same subtype of K+ channel. ATP-sensitive K+ channels are probably involved in levcromakalim- but not in a pinacidil-induced relaxation in the HIMA. In addition, in pinacidil-induced relaxation of the HIMA, K+ channel-independent mechanisms seem to be involved.

4-Aminopyridine↗

PubMed1997

Association of ventricular arrhythmias with left ventricular remodelling after myocardial infarction.

OBJECTIVE: To assess the relation between ventricular arrhythmias after myocardial infarction and left ventricular remodelling. DESIGN: Prospective study with consecutive patients. METHODS: 97 patients with acute myocardial infarction underwent serial echocardiographic examinations (days 1, 2, 3, and 7, and after 3 weeks) to determine end diastolic volume, end systolic volume, and ejection fraction; volumes were normalised for body surface area and expressed as indices. Holter monitoring was performed on the day of the final echocardiogram. Coronary angiography was performed in 88 patients before hospital discharge. RESULTS: Complex ventricular arrhythmias (defined as Lown class 3-5) were found in 16 of 97 patients. In logistic regression models, variables predictive of complex ventricular arrhythmias were end systolic volume index on admission (b = 0.054, P = 0.015) and end diastolic volume index after three weeks (b = 0.034, P = 0.012). Complex arrhythmias were also related to the increase of end diastolic and end systolic volume indices throughout the study (F = 5.62, P = 0.046, and F = 6.42, P = 0.017, respectively by MANOVA). A two stage linear regression model of ventricular volume versus time from infarct showed that both intercept (initial volume) and slope (rate of increase) were higher for patients with complex arrhythmias in both diastole and systole (P < 0.001 for all). CONCLUSIONS: Complex ventricular arrhythmias after myocardial infarction are related to the increase of left ventricular volume rather than to depressed ejection fraction. Complex arrhythmias may be an aetiological factor linking left ventricular remodelling with higher mortality, but larger follow up studies of patients with progressive left ventricular dilatation after myocardial infarction are necessary to answer these questions.

Aged↗

PubMed1996

Long-term follow up of patients with dilated heart muscle disease treated with human leucocytic interferon alpha or thymic hormones initial results.

OBJECTIVE: To determine whether giving interferon-alpha or thymomodulin in addition to conventional treatment improves cardiac function in patients with idiopathic myocarditis and idiopathic dilated cardiomyopathy. DESIGN: Single-centre, randomised, open label, parallel group comparison of conventional treatment plus interferon-alpha, conventional treatment plus thymomodulin, and conventional treatment alone. PATIENTS: 38 patients aged 19-54 years (23 men) with biopsy-proven myocarditis or dilated cardiomyopathy. 12 were treated with conventional treatment alone, 13 were treated with interferon-alpha and conventional treatment, and 13 with thymomodulin and conventional treatment. SETTING: Tertiary cardiac referral centre. MAIN OUTCOME MEASURES: Clinical evaluation, echocardiography, and Holter monitoring at baseline, 6 months, and 1 and 2 years. Radionuclide ventriculography at rest and during exercise after 2 years. Endomyocardial biopsy at baseline and after a year if the initial diagnosis was myocarditis. RESULTS: Left ventricular ejection fraction was improved in 21 (81%) of 26 patients after interferon-alpha or thymomodulin administration and in 8 (66%) of 12 conventionally treated patients (P < 0.05) at 2 year follow up. The maximum exercise time was significantly longer at 2-year follow up in patients treated with immunomodulators (mean (SEM) 5.1 (0.6) minutes for interferon-alpha and 5.0 (0.4) minutes for thymomodulin) than in conventionally treated patients (3.3 (0.4) minutes). Left ventricular ejection fraction during exercise (assessed by radionuclide ventriculography) improved in 9 of 12 patients treated with interferon-alpha, 10 of 12 patients treated with thymomodulin, and 3 of 9 conventionally treated patients at 2 year follow up. The electrocardiogram was normal in 21 (88%) of 24 patients after interferon-alpha or thymomodulin treatment and 2 (22%) of 9 conventionally treated patients. At 2 year follow up, 19 (73%) of 26 patients treated with immunomodulators and 4 (25%) of 12 conventionally treated patients had improved their functional class. CONCLUSIONS: The results suggest that treatment of idiopathic myocarditis and/or idiopathic dilated cardiomyopathy with interferon-alpha or thymomodulin induces an earlier and significantly superior clinical improvement than conventional treatment alone.

Adult↗

PubMedDate not supplied

Spontaneous ventricular arrhythmias following partial left ventriculectomy for nonischemic dilated cardiomyopathy: relation to hemodynamics and survival.

The study assessed the value of ambulatory electrocardiogram (AECG) monitoring for identification of patients who are at increased risk for cardiac death or arrhythmic event following partial left ventriculectomy (PLV). Furthermore, the impact of PLV and its hemodynamics on the occurrence of spontaneous ventricular arrhythmias was assessed in long-term survivors. In 32 idiopathic dilated cardiomyopathy patients who underwent PLV, ambulatory ECG (AECG) was performed preoperatively, early postoperatively, and 6 months and 12 months after surgery. In 17 of 19 patients who survived > 12 months after the procedure, left ventricular (LV) angiography was performed at the same time points and was used to calculate LV ejection fraction, and end-diastolic and end-systolic wall stress. During a mean follow-up of 478 +/- 405 days, 11 cardiac events occurred. Cox univariate regression revealed frequency of premature ventricular contractions > 30/hour at baseline (p = 0.0213) and duration of heart failure symptoms (p = 0.0226) as predictors of cardiac death or arrhythmic event after PLV. In a multivariate analysis, only frequency of premature ventricular contractions > 30/hour was a significant predictor. There was no change in the frequency or severity of ventricular arrhythmias after PLV. However, frequency of premature ventricular contractions correlated with LV end-diastolic stress (r = 0.35, p = 0.013), and ejection fraction (r = -0.34, p = 0.016). Preoperative AECG monitoring may help stratification of PLV patients. Serial AECG did not show that PLV influence the incidence or the complexity of spontaneous ventricular arrhythmias. In contrast, it appears that a hemodynamically "successful" procedure may decrease the incidence of ventricular arrhythmias.

Adult↗

PubMedDate not supplied

Partial left ventriculectomy and limited heart transplantation availability.

BACKGROUND AND AIM: Partial left ventriculectomy, a novel cardiac volume reduction operation, is applied in countries without a developed heart transplantation program. We sought to determine its impact in our population of patients. METHODS: Partial left ventriculectomy was performed in 38 patients during the last 4 years. Basic inclusion criteria were nonischemic dilated cardiomyopathy and poor response to medical therapy for heart failure. Hemodynamic evaluation was carried out before and after operation. A modified surgical technique of mitral valve repair and ventricle suturing was applied. RESULTS: Thirty-day, 6-month, and 2-year survival rates were 82% +/- 7%, 65% +/- 8%, and 61% +/- 9%, respectively. Duration of heart failure symptoms was the only predictor of survival (p = 0.042). A high proportion of noncardiac causes of death was noted. Functional capacity in surviving patients improved at every successive measurement up to 1 year postoperatively. CONCLUSIONS: The introduction of partial left ventriculectomy in a country with limited heart transplantation availability had a great impact on the management of end-stage heart failure and may represent the only surgical option for some patients. The average cost per patient was substantially lower when compared to heart transplantation.

Adult↗