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Biomedical subjects

S C Vlay

Publications and source records attributed to S C Vlay.

At least 19 recordsLinked to original sources
PubMed1998

Long-term patency (9 1/2 years) and atherosclerosis of a polytetrafluoroethylene (Gortex) coronary artery bypass graft.

The patency of a polytetrafluoroethylene (Gortex) graft 9 1/2 years after coronary artery bypass graft surgery (CABG) is demonstrated. While this material is not commonly used as a conduit because of limited success in the past, this case demonstrates that, given the right circumstances, long-term patency is possible. Since available conduits for CABG are quite often limited, viable alternatives may be lifesaving and require further evaluation. In addition to mechanical considerations such as size, length, and material, anticoagulation and strict management of hyperlipidemia may be critical.

Aged↗
PubMed1998

Electromagnetic interference and ICD discharge related to chiropractic treatment.

Electromagnetic interference is well known to cause false sensing in ICDs. Sources may include instrumentation involved with acupuncture, arc welding, electrocautery, diathermy, electrolysis, and transcutaneous electric nerve stimulator units as well as power lines. Patients with ICDs are cautioned to avoid exposure to these sources.

Adult↗
PubMed1998

Alternative locations for internal defibrillator electrodes.

Successful defibrillation is described in two patients in whom the defibrillating electrode was positioned in the coronary sinus and right ventricular outflow tract as alternative sites. Internal cardiac defibrillation has been successful with single or multiple endocardial electrodes, epicardial patch electrodes, and subcutaneous surface electrodes (patch, array) in varying combinations and recently with an active can electrode. While the traditional location of the endocardial electrode has been the right ventricular apex, we describe two patients in whom defibrillation was successful in alternate locations, the coronary sinus and the right ventricular outflow tract.

Aged↗
PubMed1997

Pacing induced ventricular fibrillation in internal cardioverter defibrillator patients: a new form of proarrhythmia.

Current model internal cardioverter defibrillators (ICDs) have cardioversion, defibrillation, pacemaker, and telemetry function. Telemetry documents arrhythmia and facilitates therapeutic adjustments. We report two cases of pacing induced VF terminated by the defibrillator, with the device responsible for both initiation and correction of the arrhythmia.

Arrhythmia, Sinus↗
PubMed1996

Pacemaker Twiddler's syndrome.

Twiddler's syndrome may result from pulse generator manipulation or from spontaneous rotation due to movement around an inadequately secured electrode. In this case, the electrode became coiled in the right ventricular outflow tract.

Electrodes↗
PubMed1993

Prediction of sudden cardiac arrest: risk stratification by anatomic substrate.

The prognostic importance of coronary artery anatomy to specific outcomes including ventricular tachycardia/fibrillation was evaluated in 372 consecutive patients undergoing cardiac catheterization at University Hospital at Stony Brook between 1981 and 1984. The hypothesis that proximal left anterior descending artery narrowing before the first septal perforator had a specific relationship to survival was again tested in this cohort. The population was prospectively followed for 8 years, with all clinical management decisions made independently by the patient's primary or referring physician. Multivariate statistical and life table analyses were performed after comprehensive follow-up. Significant narrowing in the proximal left anterior descending artery was associated with an increased risk of sudden cardiac death (p = 0.0002). Abnormalities of contractility in the diaphragmatic segment of the left ventricle in addition to an elevation of the left ventricular end-diastolic pressure and the presence of congestive heart failure (p < 0.05) were other contributory variables. Outcome in patients with proximal left anterior descending coronary artery disease who underwent aortocoronary artery bypass to the artery demonstrated improved survival (p < 0.05). Risk stratification of patients at high risk for sudden cardiac death is possible and may allow identification for an aggressive approach or interventional trials.

Adult↗
PubMed1991

Complications of percutaneous intra-aortic balloon pump use in patients with peripheral vascular disease.

Percutaneous intra-aortic balloon pump use may carry an increased risk for patients with peripheral vascular disease. To determine the incidence and types of associated complications, the medical records of 144 patients who underwent a total of 153 percutaneous intra-aortic balloon pump insertions were reviewed. Patients were divided into two groups. Group 1 was composed of 20 patients with a history of peripheral vascular disease. Group 2 was composed of 124 patients without such history; they underwent a total of 133 insertions. Nineteen major complications (12%) occurred, 12 in group 1 (60% of 20 insertions) and seven in group 2 (5% of 133 insertions). Major complications were further classified by their nature: embolic, occlusive, and technical. All three types of complications occurred more frequently in group 1. Embolic complications occurred more frequently in patients with aneurysms and proved the most lethal, with two of six deaths in group 1 resulting from this complication.

Aneurysm↗
PubMed1991

Emergency coronary revascularization using polytetrafluoroethylene conduits in a patient in cardiogenic shock.

There is growing awareness that a particular subset of patients with coronary artery disease who need surgical revascularization do not have autologous vein or internal mammary artery available or surgically applicable. The polytetrafluoroethylene graft has had limited use in aortocoronary bypass procedures. We describe a case of cardiogenic shock secondary to severe coronary artery disease and aortic stenosis, where the use of this synthetic graft contributed to a successful outcome. Angiographic patency was documented at 3 months follow-up. Our experience, plus a review of the literature, supports the use of polytetrafluoroethylene grafts during aortocoronary artery bypass to salvage infarcting or ischemic myocardium, when traditional autologous bypass conduits are not available or applicable.

Aged↗
PubMed1991

Short-term variability of ventricular arrhythmia and rapid assessment of drug efficacy.

Statistical criteria for suppression and aggravation of ventricular arrhythmia were defined by means of 50 short-term drug tests performed in 24 patients. Each patient's spontaneous variability (SV) was evaluated by linear regression analysis of hour-to-hour changes in ectopy during 24- to 48-hour Holter monitoring. The response to a single oral dose of disopyramide, 300 mg, flecainide, 200 mg, and propafenone, 450 mg, was measured during a trial lasting 4 hours. Lidocaine was administered intravenously in incremental doses of up to 4 mg/min and was evaluated over 3 hours. Threshold values of ventricular arrhythmia corresponding to 95% confidence limits were calculated from baseline recordings and were used to ascertain the likelihood of a true drug effect. The minimum decrease in hourly ectopy indicating arrhythmia suppression averaged 90.9%, while an increase of at least 947% was required for a proarrhythmic effect. When these efficacy criteria were applied, 16 of 50 short-term tests revealed no drug effect. In contrast, when a 70% threshold derived from studies of daily variability was employed, only 7 of 50 trials were negative. Thus individual determination of hourly arrhythmia variability yields more stringent criteria than extrapolation from day-to-day spontaneous variation.

Aged↗