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G S Pavlides

Publications and source records attributed to G S Pavlides.

15 recordsLinked to original sources
PubMed1999

Intracoronary flow velocity measurements in adjacent stenotic and normal coronary arteries during incremental intravenous dobutamine stress and intracoronary adenosine injection.

To investigate the concomitant coronary flow and hemodynamic changes induced by dobutamine and adenosine in the catheterization laboratory, we studied stenotic and adjacent normal coronary arteries in 20 patients using paired Doppler Flowires. Coronary flow velocity and hemodynamics were measured sequentially after intracoronary (ic) adenosine, during incremental iv dobutamine infusion, and after the addition of ic adenosine during sustained peak dobutamine stress (adenosine on dobutamine). Distal to stenotic arteries, average peak velocity (APV) increased significantly (from 11 +/- 5 to 16 +/- 7 cm/sec, P < 0.001) at an intermediate dose of dobutamine (20 microg/kg/min, Dobutamine20) but did not change further thereafter to peak dobutamine stress (17 +/- 7 cm/sec), despite the significant further increase in rate-pressure product (RPP). Peak stress APV did not change with adenosine on dobutamine (to 18 +/- 7 cm/sec). In normal arteries, APV increased at Dobutamine20 (from 20 +/- 7.5 to 30 +/- 12 cm/sec, P < 0.01) and further at peak dobutamine stress (to 42 +/- 10 cm/sec, P < 0.0001) always exceeding the concomitant significant increases in RPP. Peak stress APV increased further with adenosine on dobutamine (to 53 +/- 13 cm/sec, P < 0.001). Our data demonstrate that at peak dobutamine stress there is supply/demand mismatch only in stenotic arteries where coronary flow reserve is exhausted at an intermediate dobutamine dose. Furthermore, adenosine on dobutamine potentiates coronary flow heterogeneity between stenotic and normal adjacent arteries. Cathet. Cardiovasc. Intervent. 48:1-9, 1999.

Adenosine↗
PubMed1997

Predictors of long-term event-free survival after percutaneous balloon mitral valvuloplasty.

Previous studies have shown that long-term event-free survival after percutaneous balloon mitral valvuloplasty (PBMV) could be predicted by several baseline characteristics. However, the extent of the predictive variables has not been defined accurately yet. In this study, 40 baseline demographic, clinical, echocardiographic, and hemodynamic variables of 128 consecutive patients with mitral stenosis who underwent PBMV in a single institution, were analyzed in order to predict long-term event-free survival, defined as absence of death, mitral valve replacement, or repeat PBMV. Univariate survival analysis showed that age (p = 0.03), history of commissurotomy or mitral valvuloplasty (p = 0.05), calcium grade (p = 0.008), echo score (p = 0.0001), preprocedure cardiac output (p = 0.03), preprocedure valve area (p = 0.0007), postprocedure mean left atrial pressure (p = 0.0001), postprocedure valve area (p = 0.0001), postprocedure valve gradient (p = 0.013), and postprocedural mitral regurgitation (p = 0.01) were statistically significant predictors of event-free survival. Additionally, the absolute and/or relative procedural change of the following variables were found to be statistically significant predictors of event-free survival: left atrial pressure (p = 0.01), valve area (p = 0.0001), and valve gradient (p = 0.02). Multivariate Cox proportional hazard analysis indicated that when only variables available before the procedure were considered, echo score (p = 0.002) and preprocedure valve area (p = 0.0002) were found to be independent predictors of event-free survival. When both pre- and postprocedure variables were considered, echo score (p = 0.002) and postprocedure valve area (p = 0.0001) were found to be independent predictors of event-free survival. In conclusion, mitral valve morphology reflected by echo score, and baseline and postprocedure mitral valve area were found to be the strongest independent predictors of event-free survival after PBMV.

Aged↗
PubMed1997

Intramural drug delivery by direct injection within the arterial wall: first clinical experience with a novel intracoronary delivery-infiltrator system.

Local drug delivery at the lesion site in patients with coronary artery disease is being intensively studied to prevent restenosis after percutaneous coronary intervention. However, the effective penetration of the delivered agents into the vessel wall and delivery time remain considerable problems for all currently existing devices. A unique, new catheter has been invented, the infiltrator Angioplasty Balloon Catheter (IABC), which has the capability to allow intramural drug delivery by direct injection within the arterial wall. We describe the first clinical experience with this catheter. IABC is an angioplasty catheter with 3 lumens: one for inflating the balloon, one central for the guidewire, and a third for drug delivery. On the surface of the balloon there are 3 longitudinal strips of 6 injection needles, which on inflation stand 0.01" high, and are connected to the drug-delivery lumen. With inflation of the balloon, the needles penetrate the lesion, allowing drug delivery into the media of the vessel wall. We used the IABC in 17 patients (age = 58 +/- 9 years) undergoing coronary angioplasty. All patients were symptomatic, with significant lesions (13 LAD, 3 LCX, 1 RCA) and documented ischemia. Following initial dilatation with a conventional angioplasty balloon (stenosis from 72 +/- 8% to 26 +/- 14%, P < 0.001), the IABC was used to infiltrate the lesion with 0.4 ml (6,000 IU) of low-molecular-weight heparin (Fraxiparine). For the delivery, the IABC was inflated to 1-2 atm for 30-45 s, and the heparin was injected by hand in 5 s. Lesion residual stenosis and morphology remained unchanged after IABC use (26 +/- 14% to 22 +/- 11%, P = NS). In 10 patients, stent placement followed the IABC use. The decision to proceed with stent placement was made after the initial dilatation with the conventional balloon, and it was not influenced by the IABC use. Stent placement greatly improved the final result (for the whole patient group: 22 +/- 11% to 5 +/- 18%, for the stented patients: 22 +/- 13% to -7 +/- 10%, P < 0.001 for both). Hospital course was uneventful, with no electrocardiogram changes and normal cardiac enzymes for all patients. We have shown that the use of a unique new catheter (IABC) for intramural drug delivery in human patients undergoing coronary angioplasty is feasible and safe. This catheter is the first of a new generation of catheters and represents a significant step in local drug delivery. It is very promising as a vehicle to modify plaque behavior and potentially influence restenosis after angioplasty.

Adult↗
PubMed1995

Comparative results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without thrombus.

OBJECTIVES: The purpose of this retrospective study was to compare the results of transluminal extraction coronary atherectomy in saphenous vein graft lesions with and without angiographic thrombus. BACKGROUND: Percutaneous interventions in lesions with thrombus are associated with reduced procedural success and increased risk of complications. Use of the transluminal extraction catheter, which cuts and aspirates atheroma and thrombus, has been advocated as a potential revascularization strategy for lesions with thrombus. METHODS: Baseline patient characteristics, lesion morphology, immediate angiographic results, in-hospital complications and follow-up were prospectively entered into an interventional cardiology data base. The results of transluminal extraction coronary atherectomy in saphenous vein bypass grafts with angiographic thrombus were compared with results in similar grafts without angiographic thrombus. RESULTS: Transluminal extraction coronary atherectomy was performed in 175 patients with 183 vein graft lesions, including 59 lesions (32%) with thrombus (Group 1) and 124 (68%) without thrombus (Group 2). Compared with lesions in Group 2, lesions in Group 1 were associated with a higher incidence of baseline total occlusion, diffuse disease and abnormal Thrombolysis in Myocardial Infarction (TIMI) grade flow (p < 0.05); more severe diameter stenosis at baseline, after atherectomy and after final angiography (p < 0.05); a lower rate of clinical success (69% vs. 88%, p < 0.01); and more angiographic and clinical complications, including no reflow (p < 0.05), vascular repair (p < 0.05) and Q wave myocardial infarction (p = 0.09). CONCLUSIONS: In transluminal extraction coronary atherectomy of saphenous vein bypass grafts, the presence of thrombus is associated with more baseline lesion complexity, reduced clinical success and increased risk of no reflow, Q wave myocardial infarction and vascular repair.

Aged↗
PubMed1994

Emergent percutaneous cardiopulmonary bypass in patients having cardiovascular collapse in the cardiac catheterization laboratory.

Percutaneous cardiopulmonary bypass (PCB) was instituted in 30 initially stable patients who developed either cardiac arrest refractory to resuscitation (n = 7) or cardiogenic shock (mean arterial blood pressure < 50 mm Hg unresponsive to fluid resuscitation or vasopressors) (n = 23) after a catheterization laboratory complication. Events leading to collapse included abrupt closure during percutaneous transluminal coronary angioplasty (PTCA) (n = 22), complications from diagnostic cardiac catheterization (n = 6), left ventricular perforation during mitral valvuloplasty (n = 1), and right ventricular perforation during pericardiocentesis (n = 1). PCB was initiated within 20 minutes of cardiovascular collapse in 83% of patients (arrest: 21 +/- 13 minutes [range 10 to 50]; and shock: 17 +/- 6 minutes [range 10 to 30]). Mean arterial blood pressure increased on PCB from 0 to 56 mm Hg in patients with cardiac arrest and from 37 to 63 mm Hg in those with cardiogenic shock at mean PCB flow rates of 2.5 to 5.0 liters/min. Subsequent therapy on PCB included emergent cardiac surgery (n = 14), PTCA (n = 13) and medical therapy (n = 3). Six patients (20%) survived to hospital discharge (3 with cardiac surgery, 2 with PTCA, and 1 with medical therapy). All 7 patients with refractory cardiac arrest died despite further interventions on PCB, whereas 6 of 23 (26%) with cardiogenic shock survived to hospital discharge. Thus, in response to cardiovascular collapse in the catheterization laboratory, PCB does not salvage patients who do not regain a stable cardiac rhythm. PCB can stabilize patients who develop cardiogenic shock for further interventions which are lifesaving in only a minority of patients.

Aged↗
PubMed1994

The value of transesophageal echocardiography in predicting immediate and long-term outcome of balloon mitral valvuloplasty: comparison with transthoracic echocardiography.

UNLABELLED: The purpose of this study was to assess the role of transesophageal echocardiography in predicting the immediate and long-term outcome of balloon mitral valvuloplasty, and compare the results to transthoracic echocardiography. BACKGROUND: Transesophageal echocardiography accurately detects left atrial thrombi and allows better visualization of mitral valve morphology; however, its value in predicting the immediate and long-term outcome of balloon mitral valvuloplasty had not been assessed as adequately as for transthoracic echocardiography. METHODS: In 56 patients referred for balloon mitral valvuloplasty, both transesophageal and transthoracic echocardiography were performed (Group A). An echo score for both techniques was used to reflect mitral valve morphology, and its predictive value for immediate and long-term outcome of the valvuloplasty was assessed. The impact of transesophageal echocardiography in preventing procedural embolic events in those 56 patients was assessed by comparison to another group of 41 patients, who were examined only by transthoracic echocardiography prior to balloon mitral valvuloplasty (Group B). RESULTS: In Group A, transesophageal echocardiography detected left atrial thrombus in seven, while transthoracic echocardiography detected left atrial thrombus in two patients. After 2 months of warfarin therapy, a repeat transesophageal echo examination in four patients showed resolution of thrombus in three who went on to have balloon mitral valvuloplasty. Among the 52 patients who eventually had the procedure after thrombus was excluded by transesophageal echocardiography, there were no embolic events, compared to three embolic events among the 41 patients in Group B (P = 0.08). The transthoracic echocardiography scores, while slightly higher, correlated well with transesophageal echocardiography scores (r = 0.51, P < 0.001). The increase in mitral valve area did not correlate well to total transthoracic or transesophageal echocardiography scores, while it correlated negatively to valve calcification by transthoracic (r = -0.29, P < 0.05) and mobility by transesophageal echocardiography (r = -0.59, P < 0.02). At follow-up (7 +/- 4 months) nonsurvivors (7/56) had higher total scores by either transthoracic (P < 0.01) or transesophageal echocardiography (P < 0.05) compared to survivors. The percent reduction in mitral valve area was greater with age (r = 0.5, P < 0.02), time to follow-up (r = 0.67, P < 0.002), valve mobility by transthoracic echocardiography (r = 0.59, P < 0.01), and valve calcification by transthoracic echocardiography (r = 0.37, P = 0.09) and transesophageal echocardiography (r = 0.4, P = 0.07). CONCLUSIONS: Transesophageal echocardiography is superior to transthoracic echocardiography in detecting left atrial thrombi, and it may reduce the risk of embolic events following balloon mitral valvuloplasty. Assessment of mitral valve morphology by transesophageal echocardiography is complementary and not superior to assessment by transthoracic echocardiography. Mitral valve calcification and mobility appear to be the best morphological predictors of immediate and long-term outcome following balloon mitral valvuloplasty.

Catheterization↗
PubMed1992

Clinical, hemodynamic, electrocardiographic and mechanical events during nonocclusive, coronary atherectomy and comparison with balloon angioplasty.

The periprocedural events and myocardial function during nonocclusive coronary atherectomy by Rotablator or transluminal extraction catheter (TEC) may differ from events during balloon angioplasty. This may have important clinical consequences and needs to be defined further. Therefore, 17 patients undergoing Rotablator and 18 undergoing TEC atherectomy were assessed by clinical, hemodynamic and electrocardiographic monitoring and simultaneous transesophageal echocardiography. The findings were compared with similar parameters during subsequent balloon angioplasty performed in 16 of 17 patients undergoing Rotablator and 14 of 18 undergoing TEC atherectomy. Chest pain occurred more frequently during balloon inflation than during either atherectomy (p less than 0.02), whereas ST-segment and T-wave electrocardiographic changes were equally frequent. Transient second- or third-degree atrioventricular block occurred in 6 patients during Rotablator but in none during TEC atherectomy or balloon inflation (p less than 0.01 for each). Hemodynamic parameters and global left ventricular function remained unchanged during atherectomy. Regional myocardial function in the distribution of the target coronary artery, assessed by a wall motion score, was not affected during Rotablator, but deteriorated slightly during TEC atherectomy and more significantly during balloon inflation (score from 0.3 +/- 0.5 to 1.0 +/- 0.7 during TEC and 2.0 +/- 0.6 during balloon inflation, p less than 0.005 for both). Thus, chest pain is infrequent, whereas hemodynamics and global left ventricular function are preserved during Rotablator and TEC atherectomy. Transient atrioventricular block during Rotablator and regional myocardial dysfunction during TEC atherectomy may occur without significant consequences. These data suggest that these techniques may be preferable to balloon angioplasty for preserving intraprocedural left ventricular function.

Aged↗
PubMed1991

Value of transesophageal echocardiography during complex or high-risk coronary interventions in the cardiac catheterization laboratory.

The increasing complexity of coronary intervention and the limitations of hemodynamic and electrocardiographic monitoring have facilitated the introduction of new imaging techniques in the cardiac catheterization laboratory. Transesophageal echocardiography (TEE) has proved valuable for left ventricular (LV) monitoring during high-risk surgery, but its reported use in the cardiac catheterization laboratory has been limited. Accordingly, we assessed the feasibility and value of TEE during complex or high-risk coronary intervention in the catheterization laboratory. The TEE probe was successfully introduced in 53 of 54 (98%) attempted cases. The primary imaging goals were LV monitoring in 39 (74%), left main coronary artery (LMCA) imaging in 9 (17%) and both in 5 (9%) cases. LV monitoring was successful in 43 of the 44 (98%) attempted cases. In 25 (58%) of these, additional important observations were made by TEE that were not apparent by symptoms, or hemodynamic, electrocardiographic or radiographic monitoring. These included unexpected changes in regional myocardial function (n = 20), alteration in LV size (n = 2), exclusion of considered pericardial tamponade (n = 2) and detection of unsuspected mitral regurgitation (n = 1). Management of the interventional procedure was directly influenced by the findings of TEE in 11 of the 43 (26%) monitored cases. The LMCA was successfully visualized in 13 of the 14 (93%) attempted cases. In 11 of these, measurement of the stenotic lesion diameter by TEE correlated well with quantitative angiography both before (r = 0.83, standard error of the estimate = 0.01, p less than 0.002) and after (r = 0.80, standard error of the estimate = 0.03, p less than 0.005) intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Hemodynamic and metabolic effects of venoarterial cardiopulmonary support in coronary artery disease.

Coronary angioplasty was performed on 14 high-risk patients supported with venoarterial partial cardiopulmonary bypass. Hemodynamic, metabolic and physiologic parameters were monitored to assess the effect of cardiopulmonary support in conscious patients. Cardiopulmonary support caused a decrease in systolic (45 +/- 17 to 27 +/- 14 mm Hg, p less than 0.001), diastolic (23 +/- 12 to 14 +/- 8 mm Hg, p less than 0.005) and mean (29.7 +/- 13.2 to 18 +/- 9 mm Hg, p less than 0.001) pulmonary artery pressures. Aortic systolic (129 +/- 18 to 106 +/- 17 mm Hg, p less than 0.001), mean (89 +/- 19 to 84 +/- 19 mm Hg, p less than 0.05) and pulse (64 +/- 17 to 37 +/- 16 mm Hg, p less than 0.00001) pressures also decreased. Heart rate and aortic diastolic pressures were unchanged. End-systolic wall stress (122 +/- 48 x 10(3) to 96 +/- 44 x 10(3) dynes/cm2, p less than 0.001) and left ventricular end-diastolic diameter (5.7 +/- 0.8 to 5.5 +/- 0.9 cm, p less than 0.05) were reduced during partial cardiopulmonary bypass. After initiation of cardiopulmonary support, normal lactate extraction across the coronary circulation was diminished or converted to lactate production (38 +/- 23 to 2 +/- 29%, p less than 0.005). There was a marked reduction in hematocrit (41 +/- 4 to 28 +/- 5%, p less than 0.0001) and platelet count (259,000 +/- 57,600/ml to 145,900 +/- 46,000/ml, p less than 0.0001) after bypass. Cardiopulmonary bypass successfully supported all patients during balloon inflation, for an optimal angioplasty result.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Safety and efficacy of urokinase during elective coronary angioplasty.

Eighty-nine of 462 patients were treated with adjunctive urokinase during elective percutaneous transluminal coronary angioplasty (PTCA), 26% for unstable angina, 34% for intracoronary thrombus, 27% for intimal dissection, 10% for abrupt closure, and 3% for saphenous vein graft embolism. The 80 patients treated before abrupt closure (group A) were compared with 167 patients with similar profiles who did not receive urokinase (group B). Procedural success rates were similar. Adverse cardiac events (abrupt closure, myocardial infarction, emergency coronary artery bypass, or death) in group A versus group B occurred in: 1 of 30 (3%) versus 5 of 27 (18.5%) (p = 0.07) with intracoronary thrombus, 5 of 45 (9%) versus 18 of 110 (16.3%) with unstable angina, 1 of 12 (8%) versus 4 of 13 (31%) with unstable angina with intracoronary thrombus, 4 of 33 (12%) versus 14 of 97 (14.4%) with unstable angina without intracoronary thrombus, and 5 of 24 (20.8%) versus 6 of 66 (9%) with intimal dissection. Hemorrhagic complications occurred in 11% of patients who were treated with urokinase versus 9% of patients who were not (p = NS). No difference in blood transfusions existed. Thus urokinase was found to be safe during elective PTCA. In patients with intracoronary thrombus, urokinase appears to decrease the incidence of new adverse cardiac events, whereas in patients with intimal dissection it might have an adverse effect.

Angina, Unstable↗
PubMed1991

Effect of peripheral cardiopulmonary bypass on left ventricular size, afterload and myocardial function during elective supported coronary angioplasty.

Although cardiopulmonary bypass support has been increasingly used for high risk coronary angioplasty, few data exist regarding its effects on left ventricular function. Accordingly, in 20 patients changes in left ventricular size, afterload and myocardial function were assessed by continuous hemodynamic monitoring and simultaneous two-dimensional echocardiography during cardiopulmonary bypass-supported high risk angioplasty. The cross-sectional left ventricular area during bypass support remained unchanged during diastole, whereas during systole it decreased (from 29.6 +/- 11.4 to 27.6 +/- 10.4 cm2, p less than 0.05). Global left ventricular function expressed as fractional area change remained unchanged from baseline to bypass support but decreased during balloon inflation (from 0.27 +/- 0.11 to 0.17 +/- 0.09, p less than 0.001). The end-systolic meridional wall stress decreased during bypass support (from 141 +/- 75 to 110 +/- 58 x 10(3) dynes/cm2, p less than 0.02). Regional myocardial function was assessed by a wall motion score (0 = normal, 1 = hypokinesia, 2 = akinesia and 3 = dyskinesia). Regions supplied by a stenotic (greater than or equal to 50% diameter) vessel deteriorated during bypass support (score from 0.9 +/- 0.8 to 1.06 +/- 0.8, p less than 0.01), whereas regions supplied by a nonstenotic vessel did not. Regions supplied by the target vessel deteriorated further during balloon inflation (score from 0.7 +/- 0.6 to 1.7 +/- 0.75, p less than 0.001). Thus, although left ventricular size and global function remain unchanged and afterload decreases during bypass support, myocardial dysfunction in regions supplied by a stenotic vessel may occur. Furthermore, regional and global left ventricular dysfunction still occur with angioplasty balloon inflation during cardiopulmonary bypass support.

Aged↗
PubMed1990

Successful resuscitation of a patient with critical aortic stenosis and cardiac arrest by peripheral cardiopulmonary support system.

Patients with critical aortic stenosis have an increased risk of complications during diagnostic cardiac catheterization, and those who arrest are particularly difficult to resuscitate. Recent advances in therapeutic techniques may change this unfavorable prognosis, as it is illustrated in the presented case. A 68 year-old women with critical aortic stenosis sustained a cardiac arrest during diagnostic cardiac catheterization. Conventional cardiopulmonary resuscitation for 45 minutes failed to restore cardiac function and rhythm, which had degenerated to ventricular fibrillation, electromechanical dissociation, and asystole. Peripheral cardiopulmonary support system restored cardiac rhythm and blood pressure, with a subsequent successful aortic valve replacement.

Aged↗
PubMed1990

Contribution of transesophageal echocardiography to patient diagnosis and treatment: a prospective analysis.

The capability of transesophageal (TEE) versus transthoracic (TTE) echocardiography as a diagnostic tool in clinical practice was prospectively examined in 86 consecutive cases. A conclusive diagnosis was possible in 95% with TEE, whereas the same result was achieved in 48% by TTE. Specifically, TEE provided a conclusive diagnosis in 14 of 16 cases of infective endocarditis, while TTE gave this result in 4 of the 16 cases (p less than 0.001). Similarly, TEE allowed a conclusive diagnosis in 11 of 11 instances of aortic dissection, while TTE gave this indication in two cases (p less than 0.001). TEE was similarly effective in eight of eight cases of atrial thrombi, whereas TTE gave the diagnosis in three of eight cases (p less than 0.01). In five subjects with intracardiac masses, TEE gave a conclusive diagnosis in all five, whereas TTE was able to diagnose conclusively in one subject (p less than 0.02). In seven patients with mitral regurgitation, TEE gave the conclusive diagnosis in all seven and TTE was able to provide this information in four (p = NS). TEE was able to provide a conclusive diagnosis in four patients with aortic insufficiency, and TTE gave the same information in two of the four (p = NS). In 14 patients with prosthetic valve dysfunction, TEE gave the diagnosis in 12 and TTE gave it in eight patients (p = NS). Both methods gave a conclusive diagnosis in 13 out of 13 cases of mitral stenosis (p = NS). Also, TEE provided a conclusive diagnosis in eight of eight patients with adult congenital heart disease and TTE gave this information in four (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗