Bernard Tabatznik

Prognostic Significance of Ventricular Ectopic Beats with Respect to Sudden Death in the Late Postinfarction Period

The role of ventricular dysrhythmias as determinants of sudden coronary death (SCD) was studied prospectively in 160 male survivors of myocardial infarction, all under 65 years of age and in New York Heart Association (NYHA) functional class I or II. Twelve-hour electrocardiographic recordings were taken in all patients at serial intervals and analyzed for frequency and type of ventricular ectopic beat (VEB). Eighty percent showed VEBs on at least one tape recording. There have been 14 SCDs in a follow-up period ranging between 30 and 54 months, 12 in 87 patients (13.8%) with significant VEBs (frequent, unifocal, multifocal, paired or coupled, and ventricular tachycardia), and only two in 66 patients (3%) with absent or infrequent VEBs (P < 0.02).Although the number of patients in this study is small, the results show that all complex VEB forms together were associated with an excess risk of SCD, notwithstanding the absence of SCD in 27 patients with ventricular parasystole. It is suggested that the differential association with SCD between ventricular extrasystoles and parasystole in the late postinfarction period may have bearing on the mechanism of ventricular fibrillation and SCD.

Echocardiographic design of a multicenter investigation of free-living elderly subjects: the Cardiovascular Health Study.

The Framingham study has shown by M-mode echocardiography that left ventricular hypertrophy is a powerful, independent predictor for the development of coronary heart disease and that increased left atrial dimension has been associated with an increased risk of stroke. No previous population-based study has evaluated the risk factor correlates and predictive value for coronary heart disease and stroke of two-dimensional and Doppler, as well as M-mode, echocardiography. The Cardiovascular Health Study is a multi-year prospective epidemiologic study of 5201 men and women older than 65 recruited from four geographic sites in the United States. The main objectives of incorporating echocardiography were to determine whether echocardiographic indices, or changes in these indices, are (1) correlated with traditional risk factors for coronary heart disease and stroke; and (2) independent predictors of morbidity and mortality for coronary heart disease and stroke. Echocardiographic measurements of interest include those related to global and segmental left ventricular systolic and diastolic structure and function and left atrial size. For each subject, a baseline echocardiogram was recorded in super-VHS tape using a standard protocol and equipment. All studies were sent to a reading center where images were digitized and measurements were made using customized computer algorithms. Calculated data and images were stored on optical disks to facilitate retrieval and future comparisons in longitudinal studies. A second echocardiogram is scheduled in year 7, with a goal of determining whether changes in cardiac anatomy or function over a 5-year period are important predictors of morbidity or mortality from coronary heart disease and stroke. Quality control measures included standardized training of echocardiography technicians and readers, technician observation by a trained echocardiographer, periodic blind duplicate readings with reader review sessions, phantom studies, and quality control adults.

Cardiac arrhythmias on 24-h ambulatory electrocardiography in older women and men : the cardiovascular health study

OBJECTIVES This study describes the prevalence and correlates of cardiac arrhythmias in older persons. BACKGROUND Cardiac arrhythmias are frequent in selected samples of elderly persons, but their prevalence and association with cardiovascular disease and its risk factors have not been examined in a large population-based sample. METHODS In 1,372 participants in the Cardiovascular Health Study, a population-based study of cardiovascular disease risk factors, 24-h ambulatory electrocardiography was performed. RESULTS Serious arrhythmias, such as sustained ventricular tachycardia and complete atrioventricular block, were uncommon, but brief episodes of ventricular tachycardia (> or = 3 consecutive ventricular depolarizations) were detected in 4.3% of women and 10.3% of men. Ventricular arrhythmias as a group (excluding ectopic beats < 15/h) were more common in men than in women but were not significantly associated with age. The same patterns were true for bradycardia/conduction blocks. Supraventricular arrhythmias as a group (excluding ectopic beats < 15/h), in contrast, did not differ by gender but were strongly associated with increased age. Multivariate analyses showed associations with arrhythmias to differ by gender, with only one association (increased age and supraventricular arrhythmias) present in both women and men. Ventricular arrhythmias, particularly in men, were associated with a higher prevalence of cardiovascular disease and its risk factors and with subclinical disease, as measured by increased left ventricular mass and impaired left ventricular function. CONCLUSIONS Arrhythmias are common in the elderly, and their association with cardiovascular disease differs by gender. Although risk related to arrhythmias can only be determined by prospective study, such studies should have adequate power to examine potential gender differences in associations.

Unusual patterns of conduction produced by pacemaker stimuli

Abstract Four cases showing unusual patterns of conduction produced by pacemaker stimuli are presented. Some of the possible explanations for these phenomena are considered. It is suggested that the pacemaker stimuli in these cases were conducted through specialized conductive tissue rather than preferentially through the myocardial fibers. Thus, the pattern of right bundle branch block occasionally produced by transvenous catheter pacemakers in the right ventricle does not necessarily imply that the catheter has perforated the septum.

Eight-hour electrocardiogram: technique and clinical application.

The standard electrocardiogram is a sampling of but a small portion of the daily cardiac activity, and is only standardized for the supine position and the basal state. Such technique is not likely to reveal transient disturbances of cardiac rhythm and ST-T segment configuration. Accordingly, interest has been directed towards obtaining prolonged electrocardiographic recordings in ambulatory patients. A small, portable, battery-operated tape recorder capable of recording for 8-10 hours has been in use for several years (Holter, 1961; Gilson, Holter, and Glasscock, 1964). The complete system consists of three separate instruments: the tape recorder itself, called the Electrocardiocorder; a rapid playback unit, called the Arrhythmiagraph-AVSEP; and a slow playback unit called the Electrocardiocharter. The Arrhythmiagraph-AVSEP has two display screens, one superimposing all complexes on the same portion of the screen in rapid succession, and the other displaying successive R-R intervals in a bar graph array. The first reveals changes in configuration and the second changes in heart rate. A further aid is an audible tone which changes in pitch when the rate or rhythm changes. The Electrocardiocharter allows reproduction of portions of the recording in standard electrocardiographic format. In a recent clinical evaluation of this system, it was found to be most useful in evaluating obscure cerebral and cardiac symptomatology (Corday et al., 1965; Norland and Semler, 1964). In our laboratory, we were able to avoid the expense of this entire system and indeed move it one step closer to automation, by utilizing an inexpensive oscilloscope and building a simple rapid playback system.

Inexpensive presentation of data of prolonged electrocardiographic tape recordings.

Abstract Simple and inexpensive techniques for the rapid analysis of continuous electrocardiographic tape recordings are described. Permanent records, which we call the Rhythm Scan (for analysis of heart rate and rhythm) and the S-T Contour Scan (for analysis of ST-T-segment alterations) enable accurate interpretations to be made and reproduced in standard electrocardiographic format. Eight hours of continous electrocardiographic recording can be summarized on 4 feet of paper. The Scan can be produced by a technician in less than 15 minutes. These techniques can be applied to the analysis of continous electrocardiographic tape recordings from patients in an intensive coronary care unit, as well as to data obtained from ambulatory patients by the Holter technique.

Modification of the Atrial Sound by the Cold Pressor Test, Carotid Sinus Massage, and the Valsalva Maneuver

Three procedures were investigated for their effect on the atrial sound. The coldpressor test caused the atrial sound to appear in one subject and to become louder in 15 of 28 subjects; it increased the atriosystolic murmur in two subjects with mitral stenosis. These effects were at least partly independent of changes in arterial diastolic pressure and heart rate. Carotid sinus massage decreased the atrial sound in five of 10 subjects and produced an unexplained increase in one. Following release of the strain of the Valsalva maneuver the atrial sound became louder than before the strain; in seven subjects its amplitude increased progressively and the sound also migrated from the first heart sound.Increase of the atrial sound by the cold pressor test is attributed to sympathetic action upon peripheral veins, arteries, and the left atrium; its decrease by carotid sinus massage, to parasympathetic action upon these structures and the cardiac pacemaker; and its increase following release of the strain of the Valsalva maneuver, to combined increases of venous return and cardiovascular sympathetic activity. The proposed explanations require investigation by more direct methods.Sympathetic activity may contribute to the increased amplitude of atrial sounds during states of exercise and heightened emotion and, in part, for their frequent occurrence in thyrotoxicosis.