Sudden Death and Coronary Artery Anomalies

Single coronary artery originating from the right coronary sinus presented with chronic total occlusion: A case report

INTRODUCTION AND IMPORTANCE

A single coronary artery (SCA) is a rare congenital anomaly in which the artery originates from either the left or right coronary sinus. Shortly after its origin, the SCA branches into the right coronary artery (RCA), the left anterior descending artery (LAD), and the left circumflex artery (LCx). When the SCA originates from the right coronary sinus, the LAD may follow one of several abnormal courses, including the posterior atrioventricular groove, retro-aortic, interarterial, intraseptal, prepulmonic, or posterior-anterior interventricular groove. Assessing the anatomical risk and the presence of concomitant coronary artery disease (CAD) in the anomalous vessel is essential for determining the appropriate treatment.

CASE PRESENTATION

We present a very rare case of a retro-aortic LAD course originating from SCA of the right coronary sinus in a patient admitted to our clinic for evaluation of chest pain. Coronary angiography (CA) of the right coronary system revealed a SCA. RCA was occluded, with chronic total occlusion (CTO). Coronary computed tomography angiography (CCTA) was done to specify the course of LAD, which showed a SCA and a posterior course around the aorta of LAD.

CLINICAL DISCUSSION

CA is a valuable tool to identify and classify coronary artery anomalies (CAAs), but due to invasiveness, low spatial resolution, and lack of three-dimensional images, it has been progressively replaced by CCTA. CCTA is the gold standard for diagnosis of the CAAs that enabling three-dimensional visualization of the surrounding cardiac and non-cardiac structures identify patients with malignant CAAs. Taking into account the presence of SCA and CTO, the treatment option is recanalization of CTO or cardiac surgery if refractory angina is present.

CONCLUSION

When the SCA originates from the right coronary sinus, identifying the abnormal course of the LAD is critical, as it may be life-threatening. Alongside CA, CCTA plays a key role in evaluating the anatomy and associated risks of this anomaly. The appropriate treatment is determined based on the presence and severity of concomitant CAD.

Hypoplastic coronary artery disease, as a cause of sudden death

Hypoplastic coronary artery disease (HCAD) is a rare coronary artery anomaly that may be the cause of sudden death. It can involve a single or all coronary arteries. This anomaly may cause circulatory insufficiency leading to myocardial infarction. HCAD has no symptoms or may exhibit cardiovascular signs like syncope, dyspnea, chest discomfort, or dizziness. It is often diagnosed at autopsy, and early diagnosis is made with a coronary angiogram. We report HCAD as the cause of the sudden death of a 25-year-old female with a history of loss of consciousness following exertion. On autopsy, all the coronary arteries' lumen was narrowed with thin vessel walls. Histopathological examination shows an underdeveloped and missing muscular layer of the left anterior descending and circumflex coronary arteries' vascular wall. Many cases of HCAD diagnosed by radiographic imaging in living patients have been reported in the literature, but a structural anomaly of coronaries leading to HCAD has not been reported. We report a case of HCAD describing the histopathological examination findings of the vascular wall of coronary vessels illustrating the structural difference.

Stent Angioplasty in Coronary Artery Anomalies With Intramural Course: When, Why, How, With What Results?

Although coronary artery anomalies include multiple disorders, few are likely to require intervention, given that the risk for critical sequelae (ie, sudden cardiac arrest and sudden cardiac death) is generally low. This article addresses which coronary artery anomaly carriers may need intervention and which interventions may be required. The recent introduction of stent angioplasty is discussed in particular, along with general reviews of nomenclature, various anatomical and functional presentations, quantitative diagnosis methods, and indications for surgical versus percutaneous intervention. Novel criteria for defining severe stenosis also are proposed. Optimal risk quantification depends on precise imaging that only intravascular ultrasonography or optical coherence tomography can reliably obtain. Accordingly, the technique of intravascular ultrasonography-monitored stent angioplasty is described in detail. Initial results from our group's study of 100 patients with right or left anomalous origin of a coronary artery from an opposite sinus of Valsalva with intramural course are reported. Future efforts should prospectively evaluate stent angioplasty in multicenter studies based on precise, consistent techniques and follow-up protocols, such as those initiated by our group. Comparisons with surgical results should be part of the program, with the understanding that detailed and complete results from those techniques will require long-term (5- to 10-year) studies.

Causes of sudden death

Sudden cardiac death (SCD) pathophysiological point of view can be either mechanical or electrical. In case of mechanical SCD, the most frequent causes are pulmonary thromboembolism and cardiac tamponade due to intrapericardial rupture (aortic dissection, heart rupture). This distinction is important because cardiac arrest retains survival potential through cardiopulmonary resuscitation and defibrillators only if the rhythm is shockable. The heart diseases that can cause SCD vary according to the age of the individual. In young people, primary electrical diseases ('ion channel diseases') and cardiomyopathies (particularly hypertrophic and arrhythmogenic), both genetically determined and therefore potentially recurred in the proband's family, as well as myocarditis and coronary anomalies prevail; in adult-elderly populations, coronary atherosclerosis with its complications and degenerative valve diseases (aortic stenosis and mitral valve prolapse) predominate. In this short text, the main structural heart diseases characterized by electrical instability at risk of SCD will be recalled, with a focus on coronary, myocardial, and valvular diseases.

Sudden Cardiac Arrest in the Paediatric Population

Sudden cardiac arrest in the young is a rare event with a range of potential causes including cardiomyopathies, ion channelopathies, and autonomic nervous system dysfunction. Investigations into the cause involve a multidisciplinary team, including cardiologists, geneticists, and psychologists. In addition to a detailed medical history, family history and circumstances surrounding the event are important in determining the cause. Clinical investigations including an electrocardiogram are fundamental in diagnosis and should be interpreted cautiously because some children may have atypical presentations and an evolving phenotype. The potential for misdiagnosis exists that could lead to incorrect long-term management strategies. If an inherited condition is suspected, genetic testing of the patient and cascade screening of family members is recommended with genetic counselling and psychological support. Medical management is left to the treating physician acknowledging that a clear diagnosis cannot be made in approximately half of cases. Secondary prevention implantable defibrillators are widely deployed but can be associated with complications in young patients. A plan for safe return to activity is recommended along with a proper transition of care into adulthood. Broad screening of the general population for arrhythmia syndromes is not recommended; preventative measures include screening paediatric patients for risk factors by their primary care physician. Several milestone events or activities that take place in youth could be used as opportunities to promote safety. Further work into risk stratification of this paediatric population through patient registries and greater awareness of cardiopulmonary resuscitation and automated external defibrillator use in saving lives is warranted.