Barry Saul

Radionuclide simultaneous dual-isotope stress myocardial perfusion study using the three window technique

Several methods are available for performing radionuclide stress myocardial perfusion studies. All of these methods require two separate acquisition and processing iterations, which is time-consuming and inconvenient for the patient. The authors introduce a new method using the “three window technique” that they developed to perform simultaneous dual-isotope imaging for stress myocardial perfusion studies. In addition to TI-201 and Tc-99m windows centered at 70 KeV and 140 KeV, respectively, a third window centered at 105 KeV, representing scattered radioactivity from Tc-99m, is established. By subtracting the radioactivity in the third window from the radioactivity in the TI-201 window, “crosstalk” interference is significantly reduced. The simultaneous dual-isotope imaging method acquires and processes resting and stress myocardial perfusion images simultaneously. It halves imaging time and doubles patient throughput, improves scheduling flexibility, and reduces patient waiting time and discomfort.

Clinical significance of variability of ventricular late potentials detected before discharge in patients after myocardial infarction.

BACKGROUND Signal-averaged electrocardiography (SAECG) in patients after myocardial infarction (MI) is widely used to identify patients at risk for ventricular tachycardia (VT) and sudden cardiac death (SCD). It is believed that ventricular late potentials when detected after day 5 after MI are relatively stable and carry the most significant relation to subsequent arrhythmic events. This study sought to determine if ventricular late potentials in patients after MI exhibit variability when recordings were made 10 to 12 hours apart on day 7 and to assess the clinical significance of this variability. METHODS AND RESULTS SAECG was recorded in 261 patients on the 7th day after MI at 7 to 10 AM (morning) and 6 to 8 PM (evening). Forty of these patients also had recordings 30 to 40 minutes apart to determine the 95% confidence interval of variability of each parameter of SAECG. The data were analyzed with the criteria of the American College of Cardiology policy statement. A prospective analysis for the clinical end points of VT and SCD was carried out for a period of 1 year. We identified 3 groups of patients. Group 1 (54, 20.7%) had consistently positive SAECG by at least 2 abnormal parameters in both morning and evening. Group 2 (37, 14.2%) had positive SAECG at 1 time only, either morning or evening. Group 3 (170, 65.1%) had negative SAECG on both occasions. Diabetes mellitus was an independent predictor of the variability of late potentials (P <.0001). A prospective analysis for the clinical end points of VT and SCD showed that the event rate was significantly higher in group 1 than in group 2 (P <.019). CONCLUSIONS To improve the positive predictive value of SAECG in patients after MI, we advise that all positive tests be repeated 10 to 12 hours later, especially in patients with diabetes mellitus. Such testing will identify patients with consistently positive SAECG who appear to be at the highest risk for VT and SCD.

Acute Reversible Cardiomyopathy and Thromboembolism After Cisplatin and 5-Fluorouracil Chemotherapy A Case Report

Acute development of cardiomyopathy and occlusive thromboembolic events following cisplatin and 5-fluorouracil (5-FU) is rare but frequently lethal. The authors report the successful management of such an event in a 52-year-old man with squamous cell carcinoma of the soft palate. The possible pathophysiological mechanisms are discussed.

An unusual case of multiple right atrial thrombi in a patient with a dual-chamber pacemaker--a case report.

The authors present an unusual case of multiple large atrial thrombi attached to perma nent pacemaker leads identified by transesophageal echocardiography. Pathogenesis, clinical implications, and therapeutic options of pacemaker thrombi are discussed.

Gatifloxacin induced torsades de pointes.

The authors present an unusual case of torsades de pointes in an elderly woman treated with intravenous gatifloxacin antibiotic therapy.

New-onset congestive heart failure secondary to a "huge" right atrial mass--a case report.

Transesophageal echocardiography is a useful adjunct to other diagnostic modalities in uncov ering the etiology of congestive heart failure. The authors describe the case of a 75-year-old woman with a 4-week history of progressive congestive heart failure, in whom trans esophageal echocardiography played a critical role in the diagnosis of a right atrial mass, accounting for this patients constellation of symptoms.

RIGHT VENTRICULAR SYSTOLIC FUNCTION PREDICTED FROM RIGHT BUNDLE BRANCH BLOCK: VALIDATED BY CARDIAC MAGNETIC RESONANCE IMAGING

Association of right ventricular (RV) systolic dysfunction using echocardiography and electrocardiographic (ECG) features of right bundle branch (RBBB) and QRS duration was reported. The purpose of the study was to determine the correlation of ECG features of complete RBBB with parameters of RV

The Accuracy of the Electrocardiogram during Exercise Stress Test Based on Heart Size

Background Multiple studies have shown that the exercise electrocardiogram (ECG) is less accurate for predicting ischemia, especially in women, and there is additional evidence to suggest that heart size may affect its diagnostic accuracy. Hypothesis The purpose of this investigation was to assess the diagnostic accuracy of the exercise ECG based on heart size. Methods We evaluated 1,011 consecutive patients who were referred for an exercise nuclear stress test. Patients were divided into two groups: small heart size defined as left ventricular end diastolic volume (LVEDV) <65 mL (Group A) and normal heart size defined as LVEDV ≥65 mL (Group B) and associations between ECG outcome (false positive vs. no false positive) and heart size (small vs. normal) were analyzed using the Chi square test for independence, with a Yates continuity correction. LVEDV calculations were performed via a computer-processing algorithm. SPECT myocardial perfusion imaging was used as the gold standard for the presence of coronary artery disease (CAD). Results Small heart size was found in 142 patients, 123 female and 19 male patients. There was a significant association between ECG outcome and heart size (χ2 = 4.7, p = 0.03), where smaller hearts were associated with a significantly greater number of false positives. Conclusions This study suggests a possible explanation for the poor diagnostic accuracy of exercise stress testing, especially in women, as the overwhelming majority of patients with small heart size were women.

Polymorphic ventricular tachycardia during a stress test

A 70-year-old man with a history of morbid obesity, atrial fibrillation, hypertension, hypercholesterolaemia and type II diabetes mellitus was undergoing a dobutamine stress echocardiogram …

Repetitive monomorphic ventricular tachycardia associated with exercise--a case report.

The case of a 45-year-old man suffering from a catecholamine-sensitive ventricular tachycardia originating from the right ventricular outflow tract is reported. The authors describe a novel noninvasive treatment strategy for the management of this patient.