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[Changes in left ventricular function with effort in the coronary patient. l]
Insights
Coronary patients exhibit altered heart function during exercise. Angina patients show exercise-induced left ventricular dysfunction, while healed infarct patients have a rigid ventricle, and those with sequelae experience heart failure.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Exercise Medicine
Background:
- Coronary artery disease significantly impacts cardiac hemodynamics.
- Understanding left ventricular function in patients with coronary artery disease is crucial for diagnosis and management.
Purpose of the Study:
- To investigate the altered hemodynamics in coronary patients at rest and during maximal exercise.
- To differentiate left ventricular function changes based on infarction history and sequelae.
Main Methods:
- Study included 30 coronary patients.
- Hemodynamic parameters were assessed at rest and during maximal exercise using a bicycle ergometer.
- Exercise electrocardiogram was performed under standard conditions.
Main Results:
- Patients with angina of effort (no prior infarction) showed normal resting left ventricular function but acute dysfunction (reduced cardiac output, elevated end-diastolic pressure, altered compliance) during exercise-induced ischemia.
- Patients with healed infarcts (no sequelae) presented with a rigid left ventricle, normal contractility indices (dP/dt max), but abnormal myocardial compliance (negative peak dP/dt, elevated end-diastolic pressure, reduced deltaP/deltaV).
- Patients with infarction and sequelae (angina, heart failure) exhibited elevated resting filling pressures and exercise-induced cardiac failure.
Conclusions:
- Left ventricular dysfunction during exercise is a key feature in coronary patients, varying with infarction history.
- Myocardial compliance is a sensitive indicator of subclinical left ventricular abnormality in healed infarcts.
- Exercise stress testing effectively unmasks latent or worsening cardiac failure in patients with coronary artery disease and sequelae.
Abstract:
The altered haemodynamics of the coronary patient have been investigated in 30 patients both at rest and under conditions of maximal effort as carried out on the bicycle ergometer under the usual conditions for an exercise electrocardiogram. Patients with angina of effort but no previous infarction have normal left ventricular function at rest; under the ischaemia induced by exercise there is acute dysfunction of the left ventricle as witnessed by a reduction in maximal cardiac output, a raised end-diastolic pressure, and changes in compliance which are more marked than those in contractility. Patients with a healed infarct but without sequelae have a rigid left ventricle, but it is not failing; they show normal changes in dP/dt max and in the indices of left ventricular work, but a pathological form of negative peak of dP/dt, of end-diastolic pressure, and of deltaP/deltaV (which reflects myocardial compliance). Patients who have had an infarction with sequelae such as angina or attacks of left ventricular failure have filling pressures which are already elevated at rest, and cardiac failure, which becomes evident on exercise.