Regional myocardial dysfunction and hemodynamic abnormalities during strenuous exercise in dogs with limited coronary flow
| Autor: | Daniel McKown, Dean Franklin, Hitonobu Tomoike, John Ross, W. S. Kemper, Guberek M |
|---|---|
| Rok vydání: | 1978 |
| Předmět: |
Cardiac function curve
medicine.medical_specialty Physiology Strenuous exercise Physical Exertion Hemodynamics Blood Pressure Coronary Disease Sudden death Constriction Death Sudden Dogs Heart Rate Internal medicine Coronary Circulation Heart rate medicine Animals business.industry Heart medicine.disease Coronary Vessels Blood pressure Ventricular fibrillation Cardiology Cardiology and Cardiovascular Medicine business |
| Zdroj: | Circulation research. 42(4) |
| ISSN: | 0009-7330 |
| Popis: | SUMMARY We studied regional myocardial dynamics during brief, strenuous bouts of running in 12 conscious dogs by telemetry before and after partial circumflex coronary artery (CCA) constriction. Regional myocardial dimensions were measured by an ultrasonic method in a control segment (CS) and segment to be made ischemic (IS). In control runs heart rate (HR), left ventricular (LV) systolic pressure, and dP/dt increased markedly, and segment end-diastolic lengths (EDL) increased along with augmentation of regional myocardial performance. Following CCA constriction, resting hemodynamics and segment dynamics remained within the control range; during running, HR was elevated similarly to the control (approximately 280/min), but LV systolic pressure and dP/dt changes were significantly reduced. Shortening of CS did not change significantly, but IS shortening, velocity, and indices of segment power and stroke work were rapidly and markedly depressed. In two dogs, ventricular fibrillation occurred during and immediately after running. After exercise, IS shortening usually required from 5 to 10 minutes to recover to near pre-exercise levels. We conclude that when regional and total cardiac function are within the normal range at rest, strenuous exercise in the presence of coronary stenosis induces rapid, severe regional myocardial dysfunction accompanied by significant hemodynamic abnormalities and, occasionally, by sudden death. Abnormal regional wall motion during and following exercise appears to provide a specific indicator of limited coronary reserve. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|