The effect of thrombolytic therapy on left ventricular aneurysm formation in acute myocardial infarction: relationship to successful reperfusion and vessel patency.

BACKGROUND: Although there is increasing evidence for the beneficial effect of thrombolytic therapy on global left ventricular (LV) function in acute myocardial infarction (AMI), the data concerning the early effect of thrombolytic therapy on the incidence of left ventricular aneurysm (LVA) formation and its relationship to clinical and angiographic determinants are limited. HYPOTHESIS: The study aimed to determine the independent factors involved in the development of LVA and to evaluate whether thrombolytic therapy has any preventive effect on the development of LVA in AMI. METHODS: In all, 350 consecutive patients suffering from a first attack of AMI were included. Of these, 205 who arrived within 12 h of onset of symptoms received thrombolytic therapy (thrombolytic group) and the remaining 145 patients served as control group. All patients received aspirin and maximal-dose anticoagulation with intravenous heparin therapy. Early successful reperfusion was assessed by enzymatic and electrocardiographic evidence, and late vessel patency was evaluated according to Thrombolysis in Myocardial Infarction (TIMI) classification. Patients with TIMI grade 2 or 3 flow were considered to have vessel patency. RESULTS: The overall incidence of LVA was 11.7% (41/350), and no statistical difference was found between the incidence of LVA between the two groups (11.7 vs. 11.7%, p>0.05). However, the patients receiving thrombolytic therapy and exhibiting a patent infarct-related artery (PIRA) (n = 125, 61%), had a significantly reduced incidence of LVA compared with those who did not (7.2 vs. 18.8%, p= 0.015). In univariate analysis, vessel patency, proximal left anterior descending artery (LAD) stenosis, total LAD occlusion, multivessel disease, and hypertension were found to be important factors in LVA formation after AMI. After adjustment for other clinical and angiographic variables, total LAD occlusion (odds ratio [OR] 3.62,95% confidence interval [CI] 2.45-8.42, p = 0.0014), absence of PIRA (OR 2.92, 95% CI 1.41-09, p = 0.0037) and proximal LAD stenosis (OR 2.11, 95% CI 1.05-4.71, p = 0.045) remained the independent determinants of LVA formation after AMI. CONCLUSION: Our data indicate that not all patients who received thrombolytic therapy, but only those with PIRA had evidently reduced the incidence of LVA. Patients with total LAD occlusion, with proximal LAD stenosis, and without PIRA were found to have increased risk for formation of LVA after AMI. These findings indicate that the presence of vessel patency has a preventive effect on LVA formation in AMI.

Diurnal variation of QT dispersion in patients with and without coronary artery disease.

QT dispersion defined as interlead QT variability in a 12-lead electrocardiogram was proposed by Day and associates as a simple method to evaluate the repolarization heterogenicity of the ventricular myocardium. The frequency of onset of myocardial infarction and sudden death has been reported to have a circadian variation, with a peak incidence in the early morning hours. The authors investigated whether there is diurnal variation of QT interval and QT interval dispersion in healthy subjects and in patients with coronary artery disease. The study population consisted of two groups. Group I consisted of 62 subjects without coronary artery disease and group II consisted of 82 patients with coronary artery disease. Twelve-lead ECG was recorded for each patient in the morning (between 7 AM and 8 AM), afternoon (between 3 PM and 5 PM) and at night (between 11 PM and 1 AM), on the day after performance of coronary angiography. QTc dispersion was significantly higher in patients with coronary artery disease than in healthy subjects in the morning hours and afternoon (p<0.001). Although the differences were much prominent in group I than group II, both QTc dispersion of morning and afternoon were significantly greater than those at night. There were no statistically significant differences between group I and group II at nighttime with respect to maximum QTc, minimum QTc intervals, and QTc dispersion (p>0.05). In conclusion, QT dispersion shows diurnal variation with an increase in the morning hours in both patients with coronary artery disease and subjects without coronary artery disease. The mechanism of diurnal variation of QT dispersion in patients with coronary artery disease is quite different from that of healthy subjects.

Comparison of clinical echocardiographic and hemodynamic characteristics of male and female patients who underwent mitral balloon valvuloplasty.

The clinical echocardiographic and hemodynamic characteristics and outcome of male and female patients before and after valvuloplasty were evaluated. The study population consisted of 34 male and 122 female consecutive patients who successfully underwent percutaneous balloon mitral valvuloplasty (PBMV). Clinical, echocardiographic, and hemodynamic variables were compared between male and female patients. Male patients were significantly older than female patients at the time of PBMV (39 years vs 34 years p < 0.05). Mitral valve score was significantly higher in male patients (p < 0.01). The mitral valve area before PBMV in male patients was significantly less than that in female patients (0.97 +/- 0.22 cm2 vs 1.09 +/- 0.25 cm2, respectively, p < 0.05). The pulmonary artery pressures of female patients before PBMV were higher than those of males (48 mm Hg vs 40 mm Hg, respectively, p < 0.05). The restenosis rates in male and female patients at the end of the follow-up period (38 months) were 20% and 9%, respectively (p < 0.05). In conclusion, male patients are older than female patients at the time of the PBMV procedure, and male patients have worse echocardiographic parameters and restenosis rates than female patients with the exception of pre-procedural pulmonary artery pressure.

Role of activated protein C resistance in left atrial thrombogenesis in patients with mitral stenosis.

Activated protein C resistance (APC-R) is the most common inherited cause of clinically apparent venous thromboembolism. Previous data indicate that left atrial thrombus (LAT) formation is a common complication in mitral stenosis (MS) and a hypercoagulable state exists in these patients. The aim of this study was to invastigate the association between APC-R and LAT formation in patients with MS. Seventy-seven consecutive patients with rheumatic MS were included in this study. Transesophageal echocardiography was performed on all patients to assess the presence of any thrombus or spontaneous echo contrast (LASEC) in the left atrial cavity or appendage. Thirty four of the patients had LAT and 43 did not. Prevelance of APC-R was smiliar between the two groups of patients with and without LAT (23% vs 16%, p=0.425). LAT(+) patients had higher incidence of atrial fibrillation (AF, 74% vs 51%, p=0.046) and LASEC (71% vs 19%, p<0.001) compared to LAT(-) patients. On multivariate regression analysis, only the presence of LASEC achieved statistical significance as an independent risk factor for LAT formation (p=0.0001, odds ratio=9.589, 95% confidence interval [CI] =3.143-29.251). Because onunivariate analysis both LASEC and AF were associated with LAT, we also compared the prevelance of APC-R in the subgroups of patients who have these risk factors with and without LAT. There was a correlation between the presence of APC-R and LAT in the AF(+) subgroup of MS patients (p=0.033, odds ratio=8.167, 95% CI=1.001-72.812). However, the presence of APC-R was not associated with the increased risk of LAT in LASEC(+) patients (p=0.217, odds ratio=1.200, 95% CI=1.003-1.435). Although the presence of APC-R itself is not an independent risk factor for LAT formation in MS, it may increase the risk of LAT when present in combination with AF (as an additional risk factor) in these patients.

Value of dobutamine stress echocardiography for diagnosis of coronary artery disease in patients with left bundle branch blockage.

BACKGROUND: Left bundle branch blockage (LBBB) is a strong predictor of cardiovascular mortality. Non-invasive tests such as exercise-stress testing and scintigraphy studies have no diagnostic value for diagnosis of coronary artery disease (CAD) in patients with LBBB. OBJECTIVE: To study the role of dobutamine stress echocardiography (DSE) in identification of CAD in patients with LBBB. METHODS: Thirty patients (19 men and 11 women, mean age 60 +/- 8 years) with permanent, complete LBBB were studied prospectively with DSE and coronary angiography. RESULTS: Results of DSE were compared with results of coronary angiography for left anterior descending artery and either left circumflex or right coronary artery territories, or both. Significant CAD was found in left anterior descending coronary arteries in 11 patients by coronary angiography; nine of whom were identified by DSE. Significant left circumflex or right coronary artery disease, or both, was found in nine patients; eight of whom were identified by DSE. The sensitivity, specificity and accuracy of DSE for identifying CAD in left anterior descending coronary artery territory were 82, 95 and 90%, respectively. For identifying CAD in the circumflex and right coronary artery territories sensitivity, specificity and accuracy were 88, 96 and 93%, respectively. CONCLUSION: We concluded that DSE is a very sensitive, specific and accurate non-invasive test for identification of CAD, both in left anterior descending and in left circumflex and right coronary artery territories of patients with LBBB.

Single coronary artery with "high take-off" origin in a patient with rheumatic mitral stenosis--a case report.

In this case report, a patient with rheumatic mitral stenosis and R-1 subtype single coronary artery arising from the ascending aorta ("high take-off" origin) and coursing between the aorta and pulmonary artery is presented. The clinical significance and differential diagnosis are discussed. To the authors' knowledge, this is the first case reported in the literature with a single R-1 subtype coronary artery that shows "high take-off" origin.