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Biomedical subjects

D H Spodick

Publications and source records attributed to D H Spodick.

At least 253 records · Page 14Linked to original sources
PubMed1985

Diastolic time during recovery from upright exercise in persons without heart disease.

To assess the relation between heart rate and diastolic time (cardiac cycle minus electromechanical systole) during the recovery period from upright exercise, 12 normal volunteers were studied immediately after and 2 and 5 minutes after exercise in the upright position. Although heart rate was significantly lower at 5 minutes compared with 2 minutes after exercise (106 vs 116 beats/min), there was significant shortening of diastolic time (from 251 to 230 ms) and total diastole per minute (from 28,634 to 24,220 ms/min). The explanation of this phenomenon appears to be disproportionate lengthening of diastolic time at 2 minutes after exercise, which must represent physiologic response due to increased left ventricular filling as well as continuing adrenergic effects, which would be diminished at 5 minutes. This lengthening of diastolic time also would maintain decreased subendocardial blood flow caused by increased end-diastolic volume.

Adult↗
PubMed1984

Infarction-associated pericarditis. Rarity of diagnostic electrocardiogram.

To examine how often pericarditis is associated with myocardial infarction and how often it is diagnosable by electrocardiographic changes, we determined the frequency of diagnostic (Stage I) ST-segment changes in 423 consecutive patients admitted to the coronary-care unit. Careful auscultation and electrocardiography were performed at least once daily in all patients and at least twice daily in those presenting with new chest pain of any description or a pericardial rub. Thirty-one patients had pericardial rubs, usually detected within the first four days after admission. Only 1 of the 31 had diagnostic electrocardiographic changes. The 31 patients with pericarditis differed significantly from the 392 patients without pericarditis in several respects: male predominance; Killip Classes II, III, and IV; and Q-wave infarcts. However, differences in the location of the infarct and in mortality were not statistically significant. We conclude that during acute infarction-associated pericarditis the pericardial rub is the most frequent clinical sign, and ST-segment changes diagnostic of pericarditis are rare. Our findings are consistent with the confinement of pericardial involvement to the infarct zone.

Electrocardiography↗
PubMed1984

Systolic time intervals reconsidered. Reevaluation of the preejection period: absence of relation to heart rate.

Within limits, systolic time intervals are reliable reflectors of cardiac status and responses to physiologic and pharmacologic challenges, with various functional correlates. That heart rate (HR) is an important determinant of the duration of systole is well accepted, owing to its effect on left ventricular ejection time (LVET). An independent rate effect on preejection period (PEP) is disputed. Some studies in pooled normal subjects at rest showed some degree of HR-PEP covariance, leading to widespread rate correction in practical use. However, although right atrial pacing showed the expected HR-LVET relation, it consistently failed to show an HR-PEP relation. Systolic time intervals were examined from echocardiograms of a deliberately heterogeneous group comprising 50 consecutively appearing persons with sinus rhythm. There was no HR-PEP covariance (r = 0.23; p = not significant). However, our subjects were otherwise comparable to those of other investigators, in that all other relations in these subjects were as expected from studies in both pooled and paced subjects: HR with LVET (r = -0.74; p less than 0.001), PEP/LVET with ejection fraction (r = -0.85; p less than 0.001), and PEP/LVET with velocity of circumferential fiber shortening (r = -0.65, p less than 0.001). Thus, HR correction of PEP is inappropriate. All other relations are substantiated in routinely encountered, unselected subjects.

Adolescent↗