Differential effects on right ventricular function of transient right, left anterior descending and left circumflex coronary occlusions during percutaneous transluminal coronary angioplasty
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N Danchin1, Y Juilliere, F Schrijen
1Department of Cardiology, Nancy, France.
Insights
Percutaneous transluminal angioplasty of the right or left anterior descending coronary artery significantly impairs right ventricular function. This dysfunction, observed during coronary occlusion, resolves quickly after reperfusion.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Interventional Cardiology
Background:
- Right ventricular (RV) function is crucial for overall cardiac performance.
- Percutaneous transluminal angioplasty (PTCA) involves temporary coronary artery occlusion, potentially affecting RV function.
- Understanding RV response to proximal coronary artery occlusion is vital for managing ischemic heart disease.
Purpose of the Study:
- To investigate the impact of proximal coronary artery occlusion during PTCA on right ventricular function.
- To differentiate the effects of occluding the right coronary artery (RCA), left anterior descending (LAD), and left circumflex (LCx) arteries on RV performance.
Main Methods:
- Thermodilution catheters were used to assess RV function in 8 patients undergoing PTCA of the proximal RCA (Group 1), LAD (Group 2), or LCx (Group 3).
- Measurements were taken before, during, and after balloon inflation.
- Patients had single-vessel disease, no prior myocardial infarction, and normal baseline cardiac function.
Main Results:
- Cardiac index decreased during balloon inflation in all groups.
- RV ejection fraction significantly decreased in Group 1 (RCA occlusion) and Group 2 (LAD occlusion).
- RV function returned to baseline within 2 minutes after balloon deflation in Groups 1 and 2; RV function remained unchanged in Group 3 (LCx occlusion).
Conclusions:
- Brief occlusion of the proximal LAD or RCA significantly alters RV performance.
- RV dysfunction during RCA occlusion is likely due to RV free wall ischemia.
- RV dysfunction during LAD occlusion may result from septal ischemia and increased RV afterload.
Abstract:
Right ventricular function was studied by means of a thermodilution catheter before, during and after percutaneous transluminal angioplasty of the proximal right (group 1, n = 8), left anterior descending (group 2, n = 8) or left circumflex (group 3, n = 8) coronary artery. All patients had evidence of myocardial ischemia, with single-vessel disease affecting the proximal segment of one of the three major coronary arteries; no patient had had a previous myocardial infarction and all had normal cardiac function at baseline study. Cardiac index decreased during balloon inflation. Mean pulmonary artery pressure was unaffected in group 1 but increased in group 2 (from 19 +/- 5 to 31 +/- 11 mm Hg, p less than 0.01) and in group 3 (from 19 +/- 2 to 22 +/- 5 mm Hg, p less than 0.05). Right ventricular ejection fraction decreased from 62 +/- 9% to 52 +/- 10% (p less than 0.01) in group 1 and from 64 +/- 7% to 44 +/- 10% (p less than 0.005) in group 2, and returned to normal within 2 min after balloon deflation in both groups. In group 3, right ventricular ejection fraction was unchanged during balloon inflation (58 +/- 5% at baseline, 58 +/- 9% at 60 s, p = NS). Therefore, brief occlusion of the proximal segments of the left anterior descending or right coronary artery results in marked alteration of right ventricular performance that is probably caused by right ventricular free wall ischemia in the right coronary group and by the concomitant effects of septal ischemia and increased right ventricular afterload in the left anterior descending artery group.(ABSTRACT TRUNCATED AT 250 WORDS)