PubMed Health⌕ Search

Biomedical subjects

A Tsoukas

Publications and source records attributed to A Tsoukas.

18 recordsLinked to original sources
PubMed2001

Myocardial contusion presented as acute myocardial infarction after chest trauma.

A 46-year-old male patient developed an acute myocardial infarction and congestive heart failure following blunt chest trauma. Electrocardiogram (ECG) revealed acute anterior myocardial infarction. Echocardiography showed akinesis of interventricular septum, dyskinesis in apical anterior wall, and severe impairment of left ventricular overall systolic function. Coronary angiography revealed normal coronary arteries. The patient followed a low-intensity physical medicine rehabilitation program. Follow-up was without new complications or deterioration of congestive heart failure. Five months later the patient presented with fulminant acute pulmonary edema and cardiogenic shock. Cardiopulmonary resuscitation was unsuccessful.

Coronary Angiography↗
PubMed2001

Aortic transsection after blunt chest trauma.

We report a case of an 18-year-old female who developed an extensive hemothorax after blunt chest trauma. Transesophageal echocardiography (TEE) showed transsection of the aorta at the level of the isthmus and turbulent flows in several places around the aorta. We discuss the contribution of TEE for detecting traumatic injuries to the thoracic aorta.

Adolescent↗
PubMed2001

Four year follow up of aortic valve replacement for isolated aortic stenosis: a link between reduction in pressure overload, regression of left ventricular hypertrophy, and diastolic function.

OBJECTIVE: To evaluate changes in left ventricular function and the impact of ventricular hypertrophy and pressure gradient early and late after aortic valve replacement in patients with isolated aortic stenosis. DESIGN: 41 patients with isolated aortic stenosis and normal systolic function underwent cross sectional and Doppler echocardiography two months before and two weeks and four years after aortic valve replacement. RESULTS: Early after the operation, left ventricular mass index (mean (SD)) decreased from 187 (44) g/m(2) to 179 (46) g/m(2), because of a reduction in end diastolic diameter (p < 0.05). Aortic pressure gradients were reduced, as expected. Isovolumic relaxation time was reduced from 93 (20) ms to 78 (12) ms, and deceleration time from 241 (102) ms to 205 (77) ms (p < 0.05). At four years, left ventricular mass index was further reduced to 135 (30) g/m(2) (p < 0.01) as a result of wall thickness reduction in the interventricular septum (from 14 (1.6) mm to 12 (1.4) mm, p < 0.01) and the posterior wall (from 14 (1.6) mm to 12 (1.3) mm, p < 0.01). Diastolic function, expressed by a reduction in isovolumic relaxation time from 93 (20) ms to 81 (15) ms (p < 0.01) and deceleration time from 241 (102) ms to 226 (96) ms (p < 0.05), remained improved. Prolonged isovolumic relaxation time was associated with significant septal and posterior wall hypertrophy (wall thickness > 13 mm) (p < 0.05), whereas prolonged deceleration time was related to high residual gradient (peak gradient > 30 mm Hg ) (p < 0.01). CONCLUSIONS: Left ventricular diastolic function improves early after surgery for aortic stenosis in parallel with the reduction in the aortic gradient. However, prolongation of Doppler indices of myocardial relaxation and ventricular filling is observed in patients with significant left ventricular hypertrophy and a residual pressure gradient early after surgery. At four years postoperatively, diastolic function remains improved.

Aged↗
PubMed1999

Expression of FAS adjacent to fibrotic foci in the failing human heart is not associated with increased apoptosis.

Fibrosis in the heart may result from loss of myocytes, which are replaced by collagens. Apoptosis is now known to contribute to myocyte loss in the failing human heart. The mechanisms underlying the induction of cardiomyocyte apoptosis, and thus the expansion of fibrotic foci in the failing heart, are poorly understood. We hypothesized that viable heart cells adjacent to fibrotic foci might become "predisposed" to apoptosis by expression of the receptor FAS (APO1, CD95). We therefore studied the spatial relationship of FAS expression and fibrosis in patients with heart failure. Left ventricular biopsies were obtained from seven patients undergoing coronary artery bypass grafting. All patients had reduced ejection fraction but varied in New York Heart Association class score at the time of surgery. Heart cell apoptosis, fibrosis, and FAS expression were studied by propidium iodide and in situ end labeling (ISEL) of DNA, Picrosirius red staining, and immunohistochemistry. All patient samples exhibited, albeit to varying degrees, apoptosis detected by ISEL, chromatin condensation, and nuclear fragmentation. In all samples, fibrosis (collagen) was evident both perivascular and in isolated regions of scarring. Regardless of the extent of fibrosis or detectable apoptosis, FAS expression was observed in regions immediately adjacent to the fibrosis, but not in regions distal to fibrosis, nor in fibrotic areas devoid of nuclei. Expression of FAS was found adjacent to both perivascular and diffuse fibrosis, and ISEL-positive nuclei were found within cells reacting positively with anti-FAS antibodies. However, ISEL-positive nuclei were no more abundant in FAS-positive regions (67.6 +/- 5.8% of total nuclei) than in FAS-negative areas (69.5 +/- 9.8%). We conclude that expression of FAS occurs in remaining heart cells adjacent to fibrosis of either perivascular or presumed reparative origin. Although this phenomenon could contribute to the expansion of fibrotic foci, FAS-induced apoptosis in the failing heart may not be more prevalent than apoptosis initiated by other signaling mechanisms.

Aged↗
PubMed1997

Total occlusion of the left main coronary artery with preserved left ventricular function.

Two patients with total occlusion of the left main coronary artery and well preserved left ventricular function are reported. Twenty one similar cases have been reported in the world literature. All the patients had angina pectoris. Twenty one of the 23 patients (including our cases) underwent coronary artery bypass graft surgery while the other two received medical treatment. All are alive for a follow-up period of 0.4-67 months. It is concluded that in patients with chronic total occlusion of the left main coronary artery and well preserved left ventricular function, collateral flow is always extensive but insufficient to prevent angina. Functional status is greatly improved by surgery, although survival is excellent in both treated and non-treated surgically patients.

Collateral Circulation↗
PubMed1997

Communication between a nongrafted left internal mammary artery and left anterior descending coronary artery following saphenous vein bypass grafting.

A case is described in which a pericardial branch of a nongrafted left internal mammary artery communicated directly with the distal left anterior descending artery, following saphenous vein bypass grafting. This type of collateralization following coronary artery bypass surgery seems to be very rare, and perhaps could protect the myocardium from severe ischemia.

Aged↗
PubMed1997

Aneurysm of the mitral-aortic intervalvular fibrosa as a rare cause of angina pectoris: angiographic demonstration.

Aneurysms of the mitral-aortic interventricular fibrosa (MAIF) are exceptionally rare complications, commonly following aortic valve endocarditis. This report describes the angiographic findings of such an aneurysm, in a patient who developed an uncommon symptomatology of unstable angina pectoris, caused by the aneurysm's expansion against the coronary arteries. Surgical treatment is also discussed.

Aged↗
PubMed1997

Routine arterial oxygen saturation monitoring is not necessary during transesophageal echocardiography.

BACKGROUND: Transesophageal echocardiography (TEE) is now an established adjunct to routine echocardiography, its diagnostic impact making it an invaluable first-line diagnostic procedure in many cardiac conditions. However, there is no unanimity in the way the transesophageal procedure is carried out, especially with regard to the need for antibiotic prophylaxis, sedation, and the monitoring of oxygen saturation. HYPOTHESIS: This study was prospectively undertaken (1) to determine the presence and magnitude of oxygen desaturation and (2) the changes in heart rate and blood pressure following sedation for routine TEE in an unselected and consecutive group of patients to identify those at high risk. METHODS: Arterial oxygen saturation, heart rate, and systolic, diastolic, and mean blood pressure were monitored in 106 consecutive patients undergoing routine transesophageal echocardiography. Ninety-four (89%) patients received intravenous sedation with midazolam. RESULTS: Three min after midazolam administration there was a drop in oxygen saturation from 97 +/- 2.5 to 95 +/- 2.9 (p < 0.001), in systolic blood pressure from 139 +/- 19.5 to 124.8 +/- 22.2 mmHg (p < 0.001), in diastolic blood pressure from 86.6 +/- 19.9 to 77.5 +/- 17.7 mmHg (p < 0.001), and in mean blood pressure from 108.3 +/- 18 to 95.6 +/- 28.8 mmHg (p < 0.001). After introduction of the transesophageal probe and during the examination, there was a further drop in oxygen saturation with a maximum drop at the 15th min of the examination (93.7 +/- 3.7 vs. 97 +/- 2.5, p < 0.001). The maximum blood pressure drop occurred at the 12th min into recovery: systolic blood pressure dropped from 139 +/- 19.5 to 118 +/- 20.8 mmHg (p < 0.001), diastolic blood pressure from 86.6 +/- 16.9 to 75.8 +/- 17.9 mmHg (p < 0.005), and mean blood pressure from 108.3 +/- 18 to 92.5 +/- 19.4 mmHg (p < 0.01). Patients with congestive heart failure had a greater drop in oxygen saturation compared with patients who were not in heart failure (p < 0.01). Twelve patients did not receive any sedation; however, they all showed a drop in oxygen saturation from 97.8 +/- 2.3 to 94.6 +/- 3.4 (p < 0.001), with a maximum drop at the 15th min during the transesophageal examination. CONCLUSION: In patients with no chronic obstructive airway disease who are not in congestive heart failure, routine oxygen saturation monitoring is not deemed necessary during transesophageal examination. The cause of hypoxemia during the procedure is not only related to sedation but also to esophageal intubation.

Adolescent↗
PubMed1997

Significance of persistent left ventricular dysfunction during recovery after dobutamine stress echocardiography.

OBJECTIVES: This study sought to determine the duration of new or worsening left ventricular regional wall motion abnormalities (RWMAs) after dobutamine stress echocardiography (DSE) and their relation to the extent of coronary artery disease (CAD). BACKGROUND: Despite extensive reports on DSE, little is known about the duration of new or worsening RWMAs during recovery. We hypothesized that the persistence of RWMAs during recovery may be associated with the extent of CAD and therefore ischemia. METHODS: Sixty-five consecutive patients with positive results on DSE and angiographically documented CAD were studied. Each patient underwent 12-lead electrocardiography and two-dimensional echocardiography at rest, during dobutamine infusion and continuously during recovery to assess the recovery time of ischemic myocardial regions. RESULTS: All patients had at least one ischemic region during DSE. Complete resolution of RWMAs occurred within 25 min in patients with multivessel CAD, within 20 min in those with two-vessel disease and within 15 min in those with single-vessel disease (p < 0.001). The greater the wall motion score index at peak stress, the longer the duration of RWMAs into the recovery phase (p < 0.01). RWMAs persisted long after normalization of each patient's symptoms, electrocardiographic (ECG) changes, heart rate and rate-pressure product during recovery. CONCLUSIONS: We demonstrated that normalization of left ventricular RWMAs occurs after resolution of symptoms and ECG changes during recovery. The time to recovery is related to the extent of CAD and myocardial ischemia as well as to the presence or absence of collateral circulation. These findings may represent stunned myocardium after brief period of ischemia.

Adult↗
PubMed1996

Fifteen year surveillance of echinococcal heart disease from a referral hospital in Greece.

Ten cases of hydatid heart disease were treated over a 15-year period (1980-1995). Cysts were located in the left ventricular wall (four patients), right ventricular wall (one patient), interventricular septum (one patient), interatrial septum (one patient), right atrium (one patient), pericardial cavity (one patient) and in multiple loci (one patient). Apart from two asymptomatic cases, clinical manifestations included chest pain (four patients), anaphylactic shock (one patient), constrictive pericarditis (one patient), congestive heart failure (one patient) and arterial embolism (one patient). Computed tomography was found useful in the detection of hydatid cysts and also in the determination of their morphology. Magnetic resonance was performed in three patients, with satisfactory imaging. Three out of the 10 patients died: rupture of pulmonary echinococcal cyst (one patient), massive pulmonary hydatid embolism (one patient) and rupture of an undiagnosed hydatid cyst of the right atrium during cannulation for cardiopulmonary bypass (one patient). One other patient experienced recurrent systemic embolism and became hemiplegic. Six patients were successfully treated. In five patients, the cysts were excised by open heart surgery, while in one by pericardiectomy. In addition, antiparasitic drugs were successfully used in two patients with long-term satisfactory results. In conclusion, cardiac echinococcosis is associated with an increased risk of potentially lethal complications. Newer techniques of cardiac imaging have helped locate the cysts while surgical removal may offer cure. Some patients responded to specific long-term drug treatment.

Adult↗
PubMed1995

Short-term exercise training effect after myocardial infarction on myocardial oxygen consumption indices and ischemic threshold.

This study was undertaken to determine whether adaptations to short-term exercise training after myocardial infarction, could affect the response of heart rate, blood pressure and double product at submaximal workload, and the behavior of electrocardiographic ST segment depression. We studied 60 patients (group A) who underwent a modest level exercise training for 3 months and 40 patients (group B) who did not participate in this program. All these subjects were involved in the trial 1 week after discharge from the hospital. Submaximal treadmill stress test was performed after the 3-month period. The stress test duration was longer (p < .01), heart rate (p < .001), systolic blood pressure (p < .01) and double product (p < .01) at submaximal workload were lower and the onset of ST depression of 1 mm was delayed (p < .01) in group A. In conclusion, postinfarction short-term exercise training increases the exercise tolerance, decreases the heart rate, systolic blood pressure, and double product response to exercise and improves the ischemic threshold.

Adaptation, Physiological↗
PubMed1991

A new canine model for evaluating blood prosthetic arterial graft interactions.

Various models have been proposed to examine blood-prosthetic materials interactions in terms of the effect of the prosthetic material on platelet structure and function, blood coagulation and fibrinolysis, and tissue infiltrates (cellular or acellular). In addition, these models have been used to examine the change in the graft surface over time. Particular difficulties in examining graft-materials interactions include species differences, short residence time for blood-materials interactions with commonly employed short grafts, and length of study limitations with ex vivo shunts. In this paper we report a canine, carotid-aorta subcutaneous prosthetic graft model. The specific advantages of this model are the length of the graft, which allows prolonged contact of blood with the prosthetic surface; the subcutaneous location of the graft, which allows repeated sampling of blood along the graft; and the healing characteristics of canine grafts. We selected the canine model because the healing characteristics are morphologically similar to those in humans in that endothelialization of the prosthetic surface is limited. Other models, such as the pig, are favored for use when examining blood coagulation, platelet, or fibrinolytic studies; however, these models can fully endothelialize prosthetic surfaces.

Animals↗
PubMed1991

Angioscopy of arm vein infrainguinal bypass grafts.

Between January 1988 and December 1990, 56 patients underwent 66 arm vein infrainguinal bypass grafts for limb salvage. Thirty-nine grafts were intraoperatively monitored by the standard methods of continuous wave Doppler alone (30) and arteriography (9). Twenty-seven grafts were prepared and monitored by intraoperative angioscopy. No significant findings requiring intraoperative revision or correction were noted in the grafts monitored by the standard methods. However, in those grafts prepared and monitored by angioscopy, intraluminal abnormalities of the arm veins were detected and corrected in 20/27 (74%). None of the grafts prepared or monitored by angioscopy occluded within 30 days, whereas, in those grafts monitored by continuous wave Doppler and arteriography, 7/39 failed within 30 days, a primary patency rate of 32/39 (82%) (x2 with yates correction, p = 0.055). This study shows that angioscopic preparation and monitoring of arm vein bypass grafts allows the detection and correction of unsuspected intraluminal abnormalities, which appears to improve the early primary patency of arm vein infrainguinal bypass grafts.

Aged↗
PubMed1991

Persistent platelet activation by passivated grafts.

Vascular grafts in canines exhibit similar healing patterns to humans in that the graft surface forms a pseudointima over time but endothelializes only near the anastomotic sites. Thus the pseudointima at the midportion of the graft may represent a nidus for persistent platelet activation. The purpose of this investigation was to examine the effect of the maturing graft surface on platelet activation. Long Dacron subcutaneous carotid to aorta grafts (50 cm x 8 mm) were placed in nine dogs. Blood samples were obtained by direct graft puncture, at the proximal and distal ends of the graft, at 1, 24, 48, 72 hours, 1, 2, 3, 4 weeks, and monthly thereafter for 8 months. Seven sham dogs had subcutaneous grafts implanted without arterial anastomoses, and blood samples were drawn from the femoral artery. Platelet counts were determined with a platelet counter. Platelet aggregation and release of adenosine triphosphate was determined with a whole blood aggregometer by use of arachidonic acid, collagen, and adenosine diphosphate as agonists. No difference was found in platelet aggregation to collagen or adenosine diphosphate stimulation across the graft, but platelets released significantly less adenosine triphosphate to collagen and adenosine diphosphate stimulation distally versus proximally. In the graft dogs a decrease in systemic platelet counts of 50% occurred from the preoperative level which persisted over 8 months (p less than 0.01). Also less response occurred to collagen and ADP stimulated platelet aggregation in the graft animals than the sham animals during the first month of study. These data suggest that significant platelet-graft interactions occur even after the graft has formed a mature pseudointima.

Adenosine Triphosphate↗
PubMed1991

Continued experience with intraoperative angioscopy for monitoring infrainguinal bypass grafting.

Intraoperative angioscopy provides direct, in vivo, three-dimensional visualization of the interior of the blood vessels and grafts. We have shown previously that with the application of the basic principles of irrigation and with a dedicated irrigation pump that routine intraoperative angioscopy can be performed with consistent high quality results during lower extremity revascularization. In our total experience with angioscopy as a monitoring procedure during infrainguinal bypass grafting, 259 intraoperative angioscopies, during 63 femoropopliteal and 196 distal bypass grafts, were performed from May 1, 1987, to October 31, 1989. Mean total irrigation fluid used in the study was 448 ml (range, 0 to 1400 ml) with good visual quality in more than 80% of the studies. The overall failure rate was 1.5%. No complications were directly attributable to the insertion of the angioscope or the use of the pump. Based on the angioscopic findings, 124 clinical or surgical decisions were made in 259 of the angioscopies. The incidence of graft failure in this study was 8.1% (less than 30 days) and 4.8% (greater than 30 days) with a mean follow-up of 272 days. Direct inspection of the interior of the graft and native vessels at the time of surgery has resulted in the recognition of previously unsuspected vein-graft pathology. Angioscopy as the sole monitoring procedure for infrainguinal bypass grafting is safe, effective, and reliable and may not only improve the durability of these grafts but may improve our understanding of the pathogenesis of graft failure and of the progression of the underlying atherosclerotic disease.

Adult↗
PubMed1990

New angioscopic findings in graft failure after infrainguinal bypass.

We have previously shown that intraoperative angioscopy is a safe, useful, and effective method for monitoring infrainguinal bypass grafts. The videotaped recordings of the intraoperative angioscopy studies of 25 failed infrainguinal bypass grafts inserted between May 1987 and July 1989 and 3 failing grafts that were angioscoped during the subsequent graft salvage procedure were reviewed in a systematic fashion according to a fixed protocol, to identify any endovascular findings either initially missed or in which the relevance to graft failure had been unappreciated at the time of bypass grafting. We were able to identify new venous pathologic characteristics and highlight endoluminal features, of both a technical and nontechnical nature, which have a probable causal relationship to graft failure. However, the significance of some of the endovascular findings that were seen during infrainguinal bypass grafting has yet to be fully defined.

Adult↗