Impact of coronary collateral circulation on QT dispersion in patients with coronary artery disease

Effects of the coronary collateral circulation on the Tp-e interval and Tp-e/QT ratio in patients with stable coronary artery disease

BACKGROUND

The clinical utility of the Tp-e interval and Tp-e/QT ratio in the risk stratification of ventricular arrhythmic events is controversial. Therefore, we investigated the impact of CCC on these electrocardiographic indexes in the course of stable CAD.

METHODS

Two hundred three consecutive patients with stable CAD who underwent coronary angiography and had documented total occlusion of one of the major coronary arteries were enrolled in this prospective cross-sectional study. The Tp-e interval and Tp-e/QT ratio were measured by 12-lead electrocardiogram.

RESULTS

The Tp-e interval, cTp-e interval, Tp-e/QT ratio, and cTp-e/QT ratio were lower in the grade 3 CCC group compared with the others in all leads. Multivariate linear regression analyses was performed to identify the clinical factors affecting the cTp-e interval and was indicated that age (β = 0.261, P < 0.001), male sex (β = 0.334, P < 0.001), poor Rentrop grade (β = -0.228, P < 0.001), and NLR (β = 0.137, P = 0.027) were independent predictors of a prolonged cTp-e interval.

CONCLUSION

It could be concluded that the decreased dispersion of ventricular repolarization might contribute to the lower incidence of ventricular arrhythmias and SCD in CAD patients with a good CCC.

Prognostic relevance of coronary collateral circulation: clinical and epidemiological implications

Coronary collateral circulation provides an important response to ischemic heart disease and partially determines the severity of ischemic myocardial damage. Practical significance of coronary collateral circulation has long been a matter of uncertainty due to concerns about the means for gauging coronary collateral circulation and the modest populations to be representative for all patients with ischemic heart disease. It is possible that prognosis may be defined by the balance between the harm of atherosclerotic burden, and the benefit from coronary collateral circulation. Atherosclerosis acts as a potent trigger for the formation of coronary collateral circulation, but at the same time it has deleterious effects on cardiovascular morbidity and mortality. Coronary collateral circulation has a complex role in modifying the risk of cardiovascular morbidity and mortality in ischemic heart disease. A more comprehensive insight into the exact determinants of coronary collateral circulation would help establish its potential implications in clinical and epidemiological realm.

Coronary Collateral Circulation: Any Effect on P-Wave Dispersion?

Coronary collateral circulation determines the severity of ischemic myocardial damage. Increased P-wave dispersion is an independent predictor for atrial fibrillation. Consistent evidence is little about the relation between coronary collateral circulation and arrhythmia risk. In this article, the effect of coronary collateral circulation on P-wave dispersion was evaluated. Collateral grade and P-wave dispersion were ascertained in 100 patients with ≥85% diameter stenoses in left anterior descending or right coronary arteries. Left ventricular function score was also determined in all patients. Coronary collateral circulation was absent in 32 patients, whereas 68 patients had coronary collateral circulation. Patients with collateral grade ≥1 had greater left ventricular function score than did patients with collateral grade 0 ( P = .048). However, there was no significant difference between P-wave dispersion of patients with and without coronary collateral circulation ( P = .45). The presence of coronary collateral circulation failed to exert a beneficial decreasing effect on P-wave dispersion.