Eliot Schechter

Life-threatening ventricular arrhythmias induced by exercise. Cessation after coronary bypass surgery.

In three patients with clinical ischemic heart disease ventricular tachycardia developed during standard exercise testing. Despite suppressive antiarrhythmic therapy, ventricular tachycardia during exercise persisted in one patient; ventricular fibrillation requiring cardiopulmonary resuscitation developed in the other two. Coronary angiography revealed significant obstructive coronary artery disease with no ventricular aneurysm in all three patients. Aortocoronary saphenous vein bypass surgery was performed successfully without electrocardiographic or clinical evidence of intraoperative myocardial infarction. Postoperative cineangiography documented graft patency, and repeated exercise testing failed to elicit any ventricular irritability in these patients. They have remained asymptomatic with no antiarrhythmic therapy for up to 2 years postoperatively.

Predictions of coronary artery stenosis by artificial neural network

Data from angiography patient records comprised 14 input variables of a neural network. Outcomes (coronary artery stenosis or none) formed both supervisory and output variables. The network was trained by backpropagation on 332 records, optimized on 331 subsequent records, and tested on final 100 records. If 0.40 was chosen as the output distinguishing stenosis from no stenosis, 81 patients who had stenosis would have been identified, while 9 of 19 patients who did not have stenosis might have been spared angiography. The results demonstrated that artificial neural networks could identify some patients who do not need coronary angiography.

Fluoroscopy vs. Traditional guided femoral arterial access and the use of closure devices: A randomized controlled trial†

Objective: To compare the effectiveness of accessing the common femoral artery (CFA) using fluoroscopic guidance (FG) versus traditional anatomic landmark guidance (TALG) during cardiac catheterization and to determine the effect of the two modalities on the appropriateness for use of vascular closure devices (VCDs). Background: Previous studies have shown a consistent relationship between the head of the femur and the CFA, yet there is no prospective data validating the superiority of fluoroscopy‐assisted CFA access. Methods: A total of 972 patients were randomized to either FG or TALG access. The primary endpoint of the study was the angiographic suitability of the puncture site for VCD use. Secondary endpoints included arteriotomy location, time and number of attempts needed to obtain access, and the incidence of vascular complications. Results: Of these, 474 patients were randomized into the FG arm and 498 patients into the TALG arm. A total of 79.5% of patients in the fluoroscopy arm and 80.7% in the traditional arm (P = 0.7) were deemed angiographically suitable for VCD based on the arteriotomy. The fluoroscopy group had significantly less arteriotomies below the inferior border of the head of the femur (P = 0.03). Total time for sheath insertion (105.7 ± 130.7 vs. 106.5 ± 152.6 sec) and number of arterial punctures (1.1 ± 0.4 vs. 1.1 ± 0.5) did not differ among the FG and TALG, respectively. The rates of vascular complications were not different. Conclusion: The angiographic suitability for VCD was not different between FG and TALG groups. Fluoroscopy decreased the number of low arteriotomies. The time to sheath insertion, number of arterial punctures needed to obtain access, and the incidence of complications were also similar.

Iron measures in coronary angiography patients

Excess iron has been postulated as a risk factor for coronary artery disease (CAD) because of its presence in atherosclerotic lesions, its ability to oxidize low density lipoprotein cholesterol (LDLc), and its promotion of oxygen reperfusion damage after an ischemic event. Whether iron, indirectly measured by its storage protein ferritin and its transport protein transferrin, is related to CAD was examined in a consecutive series of white male (n = 457) and female (n = 114) cardiac patients. Atherosclerosis measures were analyzed in patients grouped by tertiles of ferritin. A similar analysis was done with tertiles of transferrin. Contrary to expectations, men in the third tertile of ferritin had a smaller mean number of stenoses than men in the two lower tertiles (4.9 versus 5.6 and 5.9; P = 0.027); otherwise, there were no statistically significant differences in either number of lesions or extent of arterial narrowing based on tertiles of either measure. Separate multiple logistic regression models with age, fibrinogen, LDLc and triglycerides as covariates provided no evidence that ferritin (odds ratio = 0.88 with 95% C.I. = 0.72-1.07 for men and odds ratio = 0.79 with 95% C.I. = 0.54-1.16 for women) or transferrin (odds ratio = 0.60 with 95% C.I. = 0.31-1.16 for men and odds ratio = 1.33 with 95% C.I. 0.52-3.42 for women) were important correlates of the presence of atherosclerosis in this study.

Acquired complete right bundle branch block without overt cardiac disease: Clinical and hemodynamic study of 37 patients

Abstract Thirty-seven men (mean age 42 years) with acquired right bundle branch block were evaluated by complete electrocardiographic testing, a glucose tolerance test, determination of serum lipids and total body water, chest roentgenograms, left and right heart catheterization including coronary cineangiography, and coronary sinus catheterization. One patient had a 75 percent obstructive lesion in 1 coronary artery, 4 had lesser lesions and 32 had normal coronary arteriograms. Left ventricular end-diastolic pressure was greater than 12.0 mm Hg in 33 of 35 patients, and right ventricular end-diastolic pressure was greater than 6.0 mm Hg in 28 of 29 patients, either at rest or with exercise, or both. Measurements of ventricular systolic performance were normal. Left ventriculograms were normal in 32 patients, and the ejection fraction was reduced in 5. No ventricular asynchrony was present. No patient had significant myocardial lactate production at rest, and in no case did the coronary sinus lactate level during exercise exceed the arterial level. Significant large coronary arterial obstruction could have been an etiologic determinant in only 1 of the 37 patients. The almost consistent and unique association of acquired right bundle branch block with increased end-diastolic ventricular pressure at rest or with exercise, or both, is as yet unexplained but suggests the presence of a mild diffuse abnormality of the ventricular myocardium, including some portion of the right bundle branch.

Low- versus high-dose recombinant urokinase for the treatment of chronic saphenous vein graft occlusion.

Recanalization of a totally occluded saphenous vein graft (SVG) using commercially available urokinase from human kidney cells has been shown to be effective, but the duration of infusion and complications such as allergic reactions, bleeding events, and non-Q-wave myocardial infarction have limited its acceptance. Recently, genetic engineering has allowed the synthesis of recombinant urokinase (r-UK). Patients with an occluded SVG from 37 centers were randomized to receive a 6-hour infusion of either low-dose (125,000 IU/hour) or high-dose (350,000 IU/hour) r-UK followed by up to a maximum of 18 hours of r-UK (125,000 IU/hour) via a subselective catheter directly into the occluded vein graft. The primary study end point was final preintervention achievement of Thrombolysis In Myocardial Infarction (TIMI) flow > or = 2 using core angiographic analysis. One hundred seven patients were randomized and 98 received the study drug (low dose 52 patients, high dose 46 patients). TIMI flow > or = 2 after completion of the study drug was higher in the high-dose group (51% vs 24%, p = 0.019). This difference narrowed, but a trend was still evident on the final angiogram after adjunctive mechanical intervention (72% vs 58%, p = 0.254). Bleeding complications were frequent; severe or life-threatening bleeding occurred in 12% of patients on the low dose and 11% of patients on the high dose (p = NS), including 2 intracerebral bleeds, both of which were fatal with 1 in each group. Thus, in patients with an occluded SVG, a randomized trial of direct low-dose versus high-dose r-UK infusion demonstrated increased recanalization rates (TIMI flow > or = 2) in the high-dose arm. Percutaneous revascularization of SVG with r-UK can be accomplished with acceptable success rates, but complications are frequent.

Relationship of the 1793G-A and 677C-T polymorphisms of the 5,10-methylenetetrahydrofolate reductase gene to coronary artery disease

Numerous studies have investigated the relationship between polymorphisms, in particular 677C-T and 1298A-C, of the methylene-tetrahydrofolate reductase (MTHFR) gene and coronary artery disease (CAD) with conflicting results. This study investigates the potential association of two point mutations in MTHFR, 677C-T and 1793G-A, along with other risk factors, with CAD. This is the first hospital-based study to investigate 1793G-A in this context. Genotype analysis was performed on 729 Caucasians and 66 African Americans undergoing coronary angiography using a novel PCR-based assay involving formation of Holliday junctions. Allelic frequencies for 677C-T were 66.2% C and 33.8% T for Caucasians and 90.9% C and 9.1% T for African Americans. With respect to the 1793G-A polymorphism, allelic frequencies were 94.7% G and 5.3% A for Caucasians and 99.2% G and 0.8% A for African Americans. Disease associations were examined in the Caucasian patients due to their greater genotype variability and larger number in the patient cohort. Results suggest that neither 677CT heterozygotes (OR-1.36; 95% CI 0.95 to 1.96) nor mutant homozygotes (OR-0.73; 95% CI 0.44 to 1.20) have either an increased or decreased risk for CAD compared to the 677CC genotype. Likewise, the 1793GA genotype did not demonstrate a statistically significant association with CAD compared to 1793GG patients (OR-0.79; 95% CI 0.47 to 1.33). Mean homocysteine levels (μmol/L) increased from normal to mutant for 677C-T (677CC: 10.2; 677CT: 11.0; 677TT: 11.6) and normal to heterozygous in 1793G-A (1793GG: 10.7; 1793GA: 11.5). These MTHFR polymorphisms did not contribute to the prediction of clinically defined CAD in Caucasians.

Sertraline-induced ventricular tachycardia.

Sertraline is a selective serotonin reuptake inhibitor, which is a commonly used drug for major depressive disorder. Most frequently reported adverse effects of sertraline in patients receiving 50-150 mg/d are dry mouth, headache, diarrhea, nausea, vomiting, sweating, and dizziness. We hereby report one of the few cases of sertraline-induced ventricular tachycardia, which has been for the first time objectively assessed by the Naranjo scale. We therefore urge the primary care physicians and the cardiologists to keep sertraline as a possible precipitating factor for evaluation of ventricular tachycardia.

Activated factor VII levels in patients with angiographically confirmed coronary artery disease

We have examined factor VIIa levels in consecutive consenting patients undergoing coronary angiography (n = 702) to determine if levels are related to the presence of coronary arterial narrowing and to the degree and extent of that narrowing. Both men and women with clinically defined coronary artery disease (> or = 50% stenosis in at least 1 vessel) had factor VIIa levels that were similar to men and women with less stenosis or normal coronary arteries.

Is risk factor control and guideline-based medical therapy optimal in patients with nonobstructive coronary artery disease? A Veterans Affairs study.

Background:Aggressive risk factor modification using evidence-based secondary prevention strategies is recommended in coronary artery disease (CAD). Utilization of such strategies was compared in patients with nonobstructive CAD (NOCAD) and obstructive CAD (OCAD). Methods:Patients undergoing coronary angiography (excluding normal coronary angiograms), between January 2006 and June 2006, at the Veterans Affairs Medical Center were included. Demographic, clinical and treatment data were compared between the groups at baseline and 1 year. Results:Of the 354 patients who underwent coronary angiography, 222 (63%) had follow-up data available at 12 ± 2 months. The mean age in the NOCAD (n = 119) and OCAD (n = 103) groups was similar. There was a lower prevalence of hypertension and heart failure (P < 0.05) in the NOCAD group. Compared with the OCAD group, aspirin use was similar but statin use was lower in the NOCAD group (P = 0.008). At 1 year, statin use (P = 0001) and angiotensin-converting enzyme inhibitor/angiotensin receptor blocker use (P = 0.001) were significantly lower, whereas the use of aspirin was numerically lower (P = 0.06) in the NOCAD group. Mean low-density lipoprotein cholesterol levels were at goal (<100 mg/dL) in the NOCAD group at baseline and 1 year, whereas the same slightly worsened in the OCAD group at 1 year. Conclusions:The use of evidence-based medical therapy is lower in patients with NOCAD compared with those with OCAD. Improved awareness among health care providers and a unified effort to implement secondary prevention strategies may help correct such deficiencies.