Related Experiment Videos
[Function of the left ventricle in pacing-induced angina pectoris]
Insights
Coronary arteriosclerosis significantly impairs left ventricular function during angina, reducing ejection fraction and contractility. These functional changes under angina are unpredictable based on resting heart conditions.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Context:
- Investigates left ventricular (LV) function in patients with coronary arteriosclerosis.
- Compares findings with healthy controls under resting and stress conditions.
Purpose:
- To analyze the complete pressure-flow-volume dynamics of the LV during induced angina pectoris.
- To correlate resting cardiac findings with functional changes during stress.
Summary:
- A pressure-flow-volume analysis of the left ventricle was performed in 48 patients with coronary arteriosclerosis and 15 controls during rest and atrial pacing.
- In 26 patients, angina pectoris induction led to increased regional contraction abnormalities, decreased ejection fraction, and reduced isovolumetric contractility (Vpm).
- Angina also caused increased end-diastolic ventricular pressure and decreased diastolic distensibility, with some patients showing increased end-diastolic volume via the Frank-Starling mechanism.
Impact:
- Reveals significant functional deterioration of the left ventricle during angina pectoris in coronary arteriosclerosis.
- Highlights the unpredictability of functional changes based on initial resting-state assessments.
- Provides insights into the complex interplay of cardiac mechanics and reduced ventricular distensibility during ischemic events.
Abstract:
In 48 patients with angiographically ascertained coronary arteriosclerosis and 15 patients with unconspicuous cardiac findings a complete pressure-flow-volume-analysis of the left ventricle in rest and under artificial atrial tachycardia (atrial pacing) was carried out. In 26 patients with coronary arteriosclerosis a typical angina pectoris could be induced, however, in this group a specific constellation of the findings of the initial values was not present. Under influence of angina pectoris an increase of the disturbances of the regional contraction, connected with a significant decrease of the ejection fraction and of the isovolumetric contractibility parameter Vpm. Apart from this a significant increase of the enddiastolic ventricular pressure and of the quotient deltaP/deltaV in the diastole as a sequel of a decreased distensibility of the ventricle was found. In one part of the patients as an expression of the efficacy of the Frank-Starling-mechanism also the enddiastolic volume increased. Altogether a broad spectre of the functional changes was the result, the direction and degree of severity of which could not be foreseen according to the adequate findings in rest.