Noncoronary Collateral Myocardial Blood Flow: The Human Heart's Forgotten Blood Supply

Pathways and morphologic pattern of blood supply of epicardial ganglionated nerve plexus

Detailed cardiac neuroanatomy is critical for understanding cardiac function and its pathology. However, there remains a significant gap in knowledge regarding the blood supply to the intrinsic cardiac ganglionated plexus (GP). This study addresses this by mapping the routes and morphological pattern of blood supply to the epicardial GP in a large-animal pig model (Sus scrofa domesticus). Twenty-five domestic pigs were used in the study. We demonstrate that the epicardial ganglionated nerves receive blood from both coronary and extra-cardiac arteries. The coronary arterial branches supply blood to all five subplexuses constituting the epicardial GP. In contrast, the branches of extra-cardiac arteries supply blood to target heart areas: 1) the venous part of the heart hilum on the left atrium, 2) the walls of the sinuses of the right cranial (superior cava) and 3) pulmonary veins. Uniformly, epicardial nerves and ganglia are supplied with blood via a sole epineurial arteriole which, in most cases, is the fifth/sixth-order branch of the coronary arteries. The extra-cardiac arteries supplying blood to the epicardial GP accompanied the mediastinal nerves entering the epicardium within the limits of the heart hilum. Together, the dual and triple blood supply of the epicardial nerves and ganglia suggests a protective role from an ischemic event and/or ischemic heart disease. STUCTURED ABSTRACT: This study details the anatomy of the blood supply of epicardial ganglionated nerve plexus, from which nerve fibres extend to the myocardium, heart conduction system, coronary vessels, and endocardium, in the most popular animal model of experimental cardiology and cardiac surgery - the domestic pig. Our observations demonstrate that the epicardial nerves and ganglia receive blood from both coronary and extra-cardiac arteries. The multi-source blood supply to the cardiac nerves and ganglia may offer protection against myocardial infarction ant other ischemic heart disorders.

Refractory angina pectoris: a 20-year (2003-2022) bibliometric analysis

Background

The increasing number of patients with refractory angina pectoris, combined with the aging population and improved survival rates among coronary heart disease patients, presents a significant challenge in contemporary cardiovascular medicine. The treatment of refractory angina has been an ongoing area of exploration, yet a comprehensive analysis of the existing literature on this topic is currently lacking. Therefore, this study aims to provide the first bibliometric analysis of publications related to refractory angina.

Methods

A systematic search was conducted in the Web of Science database to identify articles related to refractory angina published between 2003 and 2022. The inclusion criteria were limited to articles and reviews written in English. CiteSpace software was utilized to conduct a collaborative network analysis of countries/regions, institutions and authors, co-occurrence analysis of keywords, and co-citation analysis of authors and references.

Results

A total of 1,386 publications were identified, with an annual publication volume exhibiting fluctuation over time. American and European countries and institutions demonstrated a leading position in terms of research output. Henry TD emerged as the most prolific researcher in the field, while Mannheimer C received the highest number of citations. The primary research hotspot within this field focused on the treatment of refractory angina, with recent emphasis on emerging treatments such as stem cell therapy and the coronary sinus reducer. A significant number of clinical trials have been conducted, with a continuous focus on patient benefits, quality of life, and survival prognosis.

Conclusion

Significant progress has been made in the field of refractory angina pectoris in recent years. Novel treatment methods, including spinal cord stimulation, enhanced external counterpulsation, stem cell therapy, and the coronary sinus reducer, hold promising therapeutic prospects. However, further high-quality evidence-based research is essential to support these emerging interventions. Additionally, the development of comprehensive evidence-based guidelines for refractory angina treatment is crucial. Such guidelines would provide clinicians with a framework to navigate the complexities of treatment choices and optimize patient care in this challenging condition.

A Case of an Apical Aneurysm Caused by a Cardiac Event Involving Noncoronary Collateral Blood Flow

An 87-year-old man presented with exertional dyspnea and was admitted due to congestive heart failure. Echocardiography and left ventriculography performed after his condition improved showed an aneurysm at the left ventricular apex. However, coronary angiography showed no significant lesions and an avascular field at the apex. Computed tomography angiography revealed that the enlarged left inferior phrenic artery reached the heart and nourished the apex wall where the aneurysm was present. Looking back retrospectively, he was previously hospitalized nine years ago for epigastric pain with elevated myocardial deviation enzymes and electrocardiographic changes but no coronary artery lesions. Moreover, abnormal vascularization had already been observed 13 years ago when the aneurysm did not exit. Considering these findings, we concluded that the ventricular aneurysm in this case was caused by a vascular event involving collateral circulation from outside the heart.

A Simplest Method to Enhance the Benefits of Internal Thoracic Artery Distal Occlusion

A common element of internal thoracic artery harvesting techniques is a distal vascular clamp placement at the end of the procedure, not only to avoid bleeding, but also to increase the internal hydrostatic pressure, diameter and flow. The logic indicates that the placement of this clamp at the beginning of the dissection will allow the artery to benefit earlier from these advantages. After more than five years of experience, we present a modification in the classical technique of skeletonized harvesting of the internal thoracic artery, consisting of artery distal occlusion at the beginning of the procedure. Some of its advantages are discussed.

Epicardial Ablation Complications

The percutaneous epicardial approach has become an adjunctive tool for electrophysiologists to treat disparate cardiac arrhythmias, including accessory pathways, atrial tachycardia, and particularly ventricular tachycardia. This novel technique prompted a strong impulse to perform epicardial access as an alternative strategy for pacing and defibrillation, left atrial appendage exclusion, heart failure with preserved ejection fraction, and genetically engineered tissue delivery. However, because of the incremental risk of major complications compared with stand-alone endocardial ablation, it is still practiced in a limited number of highly experienced centers across the world.

The Human Coronary Collateral Circulation, Its Extracardiac Anastomoses and Their Therapeutic Promotion

Cardiovascular disease remains the leading global cause of death, and the number of patients with coronary artery disease (CAD) and exhausted therapeutic options (i.e., percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG) and medical treatment) is on the rise. Therefore, the evaluation of new therapeutic approaches to offer an alternative treatment strategy for these patients is necessary. A promising research field is the promotion of the coronary collateral circulation, an arterio-arterial network able to prevent or reduce myocardial ischemia in CAD. This review summarizes the basic principles of the human coronary collateral circulation, its extracardiac anastomoses as well as the different therapeutic approaches, especially that of stimulating the extracardiac collateral circulation via permanent occlusion of the internal mammary arteries.