PubMed Health⌕ Search

Biomedical subjects

D H Spodick

Publications and source records attributed to D H Spodick.

At least 415 records · Page 23Linked to original sources
PubMed1976

Differential characteristics of the electrocardiogram in early repolarization and acute pericarditis.

Electrocardiographic mimicry necessitates differentiation between acute pericarditis and early repolarization. Among 96 persons, limb-lead RST deviations occurred in all 48 with pericarditis, but only 27 with early repolarization. RS-T vectors (A RS-T) in pericarditis tended to be horizontal (25 patients) and left of the T vector, A T (28 patients); in early repolarization, A RS-T was vertical in 15 subjects and right of A T (20 subjects); P less than or equal to 0.01. RS-T depression in Lead V1 was more common in pericarditis (14 vs. two); isoelectric RS-T in Lead V6 was more common in early repolarization (10 vs. one); P less than or equal to 0.01. PR segment deviations occurred in both limb and precordial leads in pericarditis; in early repolarization they were confined to either lead group. Thus, R-ST deviations in both limb and precordial leads with horizontal A RS-T to left of A T and RS-T depression in Lead V1 favor pericarditis; vertical A RS-T and isoelectric RS-T in Lead V6 favor early repolarization.

Acute Disease↗
PubMed1976

Arrhythmias during acute pericarditis. A prospective study of 100 consecutive cases.

One hundred consecutive patients were examined to ascertain the incidence of clinically significant arrhythmias during acute pericarditis. Only seven arrhythmias, all atrial, occurred, and these only in patients with heart disease. It appears that the vulnerability of the sinus node to being engulfed by subepicardial extension of the inflammatory process is insufficient by itself to provoke arrhythmias in the absence of disease of the myocardium, valves, or coronary arteries.

Acute Disease↗
PubMed1976

Ejection time--heart rate relationship during exercise.

The slope of the regression equation for left ventricular ejection time (LVET) vs heart rate (HR) is the appropriate factor for correcting LVET for HR. Because the regression relationship varies under different conditions, we determined the LVET-HR equations for subjects (1) seated at rest on a bicycle ergometer, and (2) during uninterrupted bicycle exercise. In 18 normally active male volunteers, ages 22-37, HR and LVET were measured under the two conditions and the regression relationship for LVET on HR determined for each. Regression equations are as follows: (1) LVET = 379-1.8 HR +/- 11.0 for subjects seated at rest on a bicycle ergometer, and (2) LVET = 371-1.2 HR +/- 13.9 for subjects performing upright bicycle exercise. The slope factors (1.8 and 1.2) differed significantly (p less than 0.01). The data indicate that considerable error can result from arbitrarily applying to exercising or resting subjects a correction factor which does not fit the conditions of the data to be corrected.

Adult↗
PubMed1976

Auscultatory perception of the fourth heart sound: effects of interval form fourth to first sound (S4-S1) and aging.

A clinically heterogeneous group of 48 subjects (aged 19 to 76 years) were searched for a fourth heart sound (S4) by three independent "blind" auscultators. Phonocardiograms recorded immediately after auscultation were measured by another "blind" observer. An S4 was identified in 32 subjects (67 per cent) in phonocardiograms with nominal filter peaks of both 70 and 35 hertz. Results in these subjects revealed two groups by auscultatory performance: those with an "easily heard" and those with an "easily missed" S4. Subjects with an "easily missed" S4 were significantly younger than those with an "easily heard" S4 (31.2 +/- 2.8 years versus 50.0 +/- 4.0 years, P less than 0.001). P-R and P-S4 intervals and relative amplitude of S4 (ratio of fourth to first heart sound [S1] amplitude) were not significantly different in the two groups. Splitting of the first heart sound (S1) was observed more frequently in the phonocardiogram of patients with an "easily missed" S4, but this trend did not reach statistical significance. The interval between S4 and the low frequency component of S1 was significantly short in those with an "easily heard" S4 (49.4 +/- 4.1 msec versus 70.0 +/- 5.0 msec, P less than 0.005). The mean S4-S1 (low frequency component) interval for the group with an "easily heard" S4 approximated 1 cycle length for S4 vibrations, a finding consistent with temporal acoustic summation. An alternate hypothesis is modification of S1.

Adult↗
PubMed1976

Aortocoronary bypass surgery for ischemic heart disease: indications based on controlled trials.

One- and two-year results of aortocoronary bypass for ischemic heart disease indicate that in stable angina pectoris, at least, the operation can be beneficial, ie, superior to intensive medical therapy, in achieving certain objectives. The operation is clearly a technical success, and prospects for very long-range patency of the grafts appear to be good. An observation of great interest is symptomatic improvement in some patients with occluded grafts. The greatest success of aortocoronary bypass is improvement in quality of life for certain patients.

Angina Pectoris↗
PubMed1976

Noninvasive differentiation of cardiomyopathy from coronary disease; pulse transmission time and systolic time intervals.

Systolic time intervals and central pulse transmission time were compared in cardiomyopathy (CM) patients and age-and sex-matched patients with coronary artery disease (CAD). Significant differences were found in pulse transmission time (shorter in the CAD patients (p less than .001) and in the pre-ejection period (p less than .001), ejection time index (p less than .05), and in the ratio of the pre-ejection period to the left ventricular ejection time (p less than .001); all were markedly abnormal in the CM group. Pulse transmission time differences may have been the result of more generalized arteriosclerotic disease in the CAD patients. It appears that both systolic time intervals and pulse transmission time clearly distinguish CM from CAD.

Cardiomyopathies↗
PubMed1976

Heart rate--left ventricular ejection time relations. Variations during postural change and cardiovascular challenges.

Regression equations for heart rate (HR)--ejection time (LVET) relations provide the appropriate factors for predicting or correcting left ventricular ejection time at any HR. We investigated HR-LVET regressions under different conditions common to both physiological and clinical studies of LVET which had been selected because of predictably different physiological responses. Ten normal subjects were studied during both supine and sitting rest and during isometric handgrip (IHG) in both supine and sitting postures and 10 during head-up tilt. Unexpectedly, as compared with pre-exercise rest on a bicycle ergometer, the slope for the resting state on a chair was slightly flatter, and LVET values were uniformly higher throughout the range of HRs measured. Differences among HR-LVET slopes and intercepts appeared to reflect the established behaviour of stroke volume and ejection rate under the conditions studied. Differences observed among intercepts, especially in supine vs. upright postures, are substantial and require that the appropriate intercept be applied in predicting LVET at a given HR. differences among slopes, while not statistically significant, may, under practical conditions, lead to unacceptable error if the appropriate slope factor is not used in correcting LVET for HR.

Adult↗
PubMed1976

Duration of diastole versus cycle length as correlates of left ventricular ejection time.

Studies were done on 82 normal subjects to evaluate cycle length versus duration of diastole as determinants of left ventricular ejection time. Cycle length and its reciprocal, heart rate, had the highest correlation with left ventricular ejection time. Removal of the self-correlation of left ventricular ejection time within cycle length reduces the correlation so that, of all intervals, duration of diastole had the highest correlation as a determinant of left ventricular ejection time. Cycle length and heart rate remain valuable as spuriously close but not misleading correlates for predicting or correcting left ventricular ejection time.

Adult↗
PubMed1976

Noninvasive stress testing. Methodology for elimination of the phonocardiogram.

Measurement by systolic time intervals (STI) of cardiac responses requires extremely careful recording during actual stress test performance. Previous work indicated no significant changes in the pulse transmission time (PTT) during exercise and other challenges. Since external STI depend on the carotid pulse offset by the PTT as an aortic curve equivalent, stable PTT implies that timing of the carotid upstroke (CARu) and the carotid incisura (CARIN) would respectively track the pre-ejection period (i.e., the externally calculated onset of the aortic upstroke) and the aortic incisura which is externally timed by the aortic component of SII (IIA). In ten subjects, STIs were recorded at supine rest, sitting, standing, during prompt and sustained squatting and during isometric and dynamic exercise. The results demonstrated the tracking of both points: regression slopes and correlation coefficients were close to 1.00 for each series and for each subset. Coefficients of correlation (r) and of determination (r2) were uniformly high for all challenges except isometric handgrip (IHG). Since left ventricular ejection time is obtained directly from the pulse curve, with the exception of IHG, STI responses during stress testing can be measured without a phonocardiogram.

Adult↗
PubMed1976

Audibility of S1.

Explore the source record for details and available documents.

Heart Auscultation↗
PubMed1976

Clavicular Auscultation. Preferential clavicular transmission and amplification of aortic valve murmurs.

Clavicular transmission of aortic valve murmurs was investigated in 15 consecutive patients. In all patients, transmission to the clavicle of aortic systolic murmurs was detected both by auscultation and by phonocardiographic studies. Of seven patients with aortic diastolic murmurs, auscultation revealed clavicular transmission in six, but only four were recordable. There was increased murmur amplitude over the clavicle in 13 out of 15 cases. In contrast, murmurs were attenuated over the subclavian artery in eight out of nine and over the carotid artery in nine out of 11 patients. We conclude that clavicular auscultation regularly discloses aortic valve murmurs. The aortic systolic murmurs are consistently propagated to the clavicle, where they are usually conspicuously amplified. Aortic systolic murmurs are less frequently transmitted to the carotid and subclavian arteries, where they are usually considerably attenuated. Clavicular auscultation appears to be more rewarding than the traditional search for transmission of aortic murmurs to the carotid artery.

Aortic Valve Insufficiency↗