Anatomy of the septal perforating arteries of the heart

The septal perforating arteries of the heart usually branch off from the anterior and inferior interventricular arteries and supply the interventricular septum and the conduction system therein. Since the septal perforating arteries are not directly visible from the outside of the heart, their anatomy and variations might be overlooked. However, the septal perforating arteries have their unique anatomy that needs to be recognized to avoid the damage of the vessels especially during common cardiac procedures such as the coronary artery bypass graft, percutaneous coronary intervention, and aortic valve replacement. A better understanding of these important arteries will help physicians to enhance the overall cardiac care for their patients. Therefore, this article discusses the anatomy, the relationship to the conduction system of the heart and the clinical significance of the septal perforating arteries.

Gender differences in outcomes following isolated coronary artery bypass grafting: long-term results

Background

The main purpose of this study was to evaluate the impact of gender on outcomes after isolated coronary artery bypass grafting, in terms of 5-year rates of overall death, cardiac-related death, myocardial infarction, re-hospitalization, repeat percutaneous or surgical revascularization, stroke, new pacemaker implantation, postoperative renal failure, heart failure and need for long-term care.

Methods

Two propensity-score matched cohorts, each of 1331 patients, undergoing isolated surgical coronary revascularization at the regional public and private centers of Emilia-Romagna region (Italy) from January 1st 2003 to December 31th 2013, were used to compare long-term outcomes of male (5976 patients) versus female gender (1332 patients).

Results

In the matched cohort, males received significantly more bypass grafts (3.0 ± 1.0 vs 2.8 ± 1.0, p = 0.001). Left internal mammary artery use and total arterial revascularization were similarly performed in both matched subgroups. Both groups reported similar cumulative rate of all-cause, cardiac-related mortality and stroke at five years. Females experienced significantly higher rate of myocardial infarction, and not significantly higher occurrence of heart failure, and need for long-term care. Males experienced significantly higher rate of cumulative re-hospitalization and higher need for pacemaker implantation. Female gender was not an independent predictor of death at long-term follow-up.

Conclusions

Women are more likely to be readmitted with myocardial infarction and congestive heart failure after CABG but experience survival similar to that observed in men. Female gender was not an independent risk factor for mortality. Prevention of new occurrence of postoperative myocardial infarction and enhancement of complete coronary revascularization should be future endpoints.

Prevalence and characterization of coronary artery disease in patients with symptomatic bradyarrhythmias requiring pacemaker implantation

Background

This study was conducted to assess the prevalence and characterization of CAD in high risk patients requiring pacemaker implantation for symptomatic bradyarrhythmias.

Methods

This study included 100 patients with symptomatic sinus node dysfunction or atrioventricular block, who were at high risk of CAD or had previously documented atherosclerotic vascular disease (ASCVD). Coronary angiography was performed before pacemaker implantation. CAD was defined as the presence of any degree of narrowing in at least one major coronary artery or its first order branch. Obstructive CAD was defined as ≥50% diameter stenosis. CAD was categorized as single vessel disease (SVD), double vessel disease (DVD), or triple vessel disease (TVD); and obstructive CAD in the arteries supplying the conduction system was sub-classified according to Mosseri's classification.

Results

Out of 100 patients (mean age 64.6 ± 10.7 years), 45 (45%) had CAD. 29% patients had obstructive CAD while 16% had non-obstructive CAD. 53.3% patients had SVD, 15.6% had DVD and 31.1% had TVD. Among patients with obstructive CAD; Type I, II, III and IV coronary anatomies were present in 6.9%, 34.5%, 10.3% and 48.3% patients respectively. Presence of CAD significantly correlated with dyslipidemia (p = 0.047), history of smoking (p = 0.025), and family history of CAD (p = 0.002).

Conclusion

Angiographic CAD is observed in a substantial proportion of patients with symptomatic bradyarrhythmias and risk factors for CAD. It could be argued that such patients should undergo a coronary work-up before pacemaker implantation. Treatment of concomitant CAD is likely to improve the long term prognosis of these patients.

Reversibility of High-Grade Atrioventricular Block with Revascularization in Coronary Artery Disease without Infarction: A Literature Review

Complete atrioventricular (AV) block is known to be reversible in some cases of acute inferior wall myocardial infarction (MI). The reversibility of high-grade AV block in non-MI coronary artery disease (CAD), however, is rarely described in the literature. Herein we perform a literature review to assess what is known about the reversibility of high-grade AV block after right coronary artery revascularization in CAD patients who present without an acute MI. To illustrate this phenomenon we describe a case of 2 : 1 AV block associated with unstable angina, in which revascularization resulted in immediate and durable restoration of 1 : 1 AV conduction, thereby obviating the need for permanent pacemaker implantation. The literature review suggests two possible explanations: a vagally mediated response or a mechanism dependent on conduction system ischemia. Due to the limited understanding of AV block reversibility following revascularization in non-acute MI presentations, it remains difficult to reliably predict which patients presenting with high-grade AV block in the absence of MI may have the potential to avoid permanent pacemaker implantation via coronary revascularization. We thus offer this review as a potential starting point for the approach to such patients.

Reversibility of atrioventricular block according to coronary artery disease: results of a retrospective study

Background and Objectives

The causal relationship of clinically-significant atrioventricular block (AVB) and coronary artery disease (CAD) is uncertain. We investigated whether CAD is related to irreversible AVB that requires treatment with a permanent pacemaker.

Subjects and Methods

We included 188 consecutive patients with new-onset AVB considering pacemaker, who had undergone invasive or noninvasive coronary evaluation. Patients were divided into one of 2 groups: irreversible AVB who underwent implantation of permanent pacemaker {irreversible block (IB) group, n=173} or reversible AVB {reversible block (RB) group, n=15}.

Results

In IB group, significant CAD was observed in 44 patients (25.4%) and there were 2 (1.2%) patients with acute myocardial infarction (AMI). In RB group, 14 patients (93.3%) had CAD (p<0.001) and 13 patients (86.7%) presented with AMI (p<0.001). On the aspect of CAD type and reversibility of AVB, 13/15 (86.7%) patients of AMI, 0/2 (0%) of unstable angina, and 1/41 (2.4%) of stable angina had reversible AVB.

Conclusion

AVB in patients with AMI is usually reversible. Therefore, permanent pacemaker implantation should be delayed in cases of AMI. AVB in patients with CAD other than AMI is usually irreversible.

Relation of QRS width in healthy persons to risk of future permanent pacemaker implantation

In the setting of acute myocardial infarction, prolongation of the QRS interval on electrocardiography identifies patients at risk for needing permanent pacemaker implantation. However, the implications of prolonged QRS intervals in healthy subjects are unclear, especially given that the QRS prolongation encountered in this setting is typically mild. The aim of this study was to assess the relation between QRS duration and incident pacemaker implantation in a community-based cohort of 8,311 subjects (mean age 54 years, 55% women) who attended 17,731 routine examinations with resting 12-lead electrocardiography. QRS duration was analyzed as a continuous and a categorical variable (<100, 100 to <120, and > or =120 ms). During up to 35 years of follow-up, 157 participants (56 women) developed need for permanent pacemakers. In multivariable Cox regression models adjusting for cardiovascular risk factors and previous myocardial infarction or heart failure, mild QRS prolongation was associated with a threefold risk for pacemaker implantation (adjusted hazard ratio 2.90, 95% confidence interval 1.81 to 4.66, p <0.0001), and bundle branch block was associated with a fourfold risk for pacemaker implantation (hazard ratio 4.43, 95% confidence interval 2.94 to 6.68, p <0.0001). Each standard deviation increment in QRS duration (11 ms) was associated with an adjusted hazard ratio of 1.14 (95% confidence interval 1.11 to 1.18, p <0.0001) for pacemaker placement. This association remained significant after excluding subjects with QRS durations > or =120 ms. In conclusion, subjects with prolonged QRS durations, even without bundle branch block, are at increased risk for future pacemaker implantation. Such individuals may warrant monitoring for progressive conduction disease.

Anomalous right coronary artery originating from the left anterior descending artery: case report and review of the literature

The anomalous origin of the right coronary artery (RCA) as a branch of the left anterior descending (LAD) artery is a very rare variation of single coronary artery. At least 36 cases have been described previously in the literature. The vast majority of previous reports have described a single anomalous vessel with its origin after the first septal perforator of the LAD, which courses anterior to the right ventricular outflow tract to reach territory normally served by the right coronary artery. Of 35 cases in structurally normal hearts, 19 (54%) patients had >50% narrowing in one or more epicardial coronary arteries (54%), at least 14 (40%) of whom required revascularization. Thirteen cases (37%) did not have significant coronary artery disease, while the remaining 3 cases were unclear. The current report reviews previous reports of this anomaly and describes a patient with an anomalous RCA from the mid-LAD, in whom heart block, back pain and dyspnea was the initial manifestation of ischemia. On heart catheterization, there was significant coronary artery disease in the LAD proximal to the origin of the anomalous artery. The patient was successfully revascularized with a unique sequential left internal mammary artery bypass to the anomalous vessel and LAD.