Proximal circumflex coronary artery in the atrioventricular groove usually has large diameters. Arterial diameters in this region vary from 2.5 to 5 mm. Revascularization of this part of the circumflex artery allows good distal anastomosis configuration and better long-term patency rate.

Atrial fibrillation (AF) is one of the most common arrhythmias encountered in clinical practice. The pathophysiological mechanisms responsible for its development are complex, vary amongst individuals, and associated with predisposing factors. Here, we report a case of AF caused by annular constrictive pericarditis (ACP), which is extremely rare due to its unusual anatomical form. In our patient, AF was refractory to multiple antiarrhythmic medications; however, spontaneous conversion to sinus rhythm occurred when the ring encircling the right and left ventricular (RV and LV) cavities along the atrioventricular (AV) groove was severed. This suggests that atrial stretch due to atrial enlargement and increased left atrial (LA) pressure may contribute to the initiation and maintenance of AF. This report highlights the importance of the careful investigation of rare predisposing factors for AF using non-invasive diagnostic approaches and mechanical-electric feedback (MEF) as a pathophysiological mechanism for AF initiation and maintenance.

BACKGROUND: The left atrial assist device (LAAD) is a novel pump that was developed specifically for the treatment of heart failure with preserved ejection fraction. The device is surgically implanted in the mitral position. This study aimed to characterize the various device-fitting configurations in the mitral annular position.
METHODS: Rapidly prototyped LAAD models (n = 5) were fabricated with five different driveline configurations: (A) annulus level/intra-cuff running; (B) supra-cuff/below coronary sinus (CS); (C) infra-cuff; (D) supra-annulus/supra-CS; (E) left ventricular free wall level. The 3D-printed models were implanted in extracted fresh porcine hearts (80-100 kg, adult, healthy porcine) and the proximity of anatomical structures between the driveline and CS and coronary artery (CA) were measured.
RESULTS: All five device configurations were evaluated for fitting. For the purpose of preventing blood clot formation around the driveline, the mitral annulus (MA) as a driveline pass-way (configuration A) has been considered advantageous with the current device, in that the driveline exposure to blood has been avoided. The CS does not exist at exactly the same level as the MA, and there is less risk of injuring it than using the left atrial free wall. However, there is an inevitable risk of damaging the CA, so careful visual inspection before inserting the driveline is needed.
CONCLUSIONS: Several options of driveline exteriorization were demonstrated, and the safety of each configuration was evaluated. Using the MA as a pathway for the driveline exit is considered to be a reasonable and safe method.

Constrictive pericarditis is caused by fibrosis and calcification of the pericardium, processes that inhibit diastolic filling of the heart. For the diagnosis of constrictive pericarditis, a combined approach is used to evaluate the morphologic pericardial abnormalities in conjunction with assessment of the functional and hemodynamic changes. We report novel findings of chest computed tomography (CT) and chest roentgenogram with respect to a ring-shaped pericardial calcification on atrioventricular groove causing strangulation of the heart in the patient with constrictive pericarditis, which is anatomically rarer than other severe cases of constrictive pericarditis encasing the entire heart.

Noninvasive imaging of coronary artery disease is rapidly replacing angiography as the first line of investigation. Multislice CT is the non-invasive modality of choice for imaging coronary artery disease and provides high speed with good spatial resolution. CT coronary angiography in addition to detecting and characterising atherosclerotic coronary artery disease is also a good imaging tool for evaluating anomalies of coronary arteries. Superdominant right coronary artery with absent left circumflex artery is one such rare coronary artery anomaly which is well evaluated with multislice CT angiography. The authors report one such case of superdominant right coronary artery with absent left circumflex artery imaged with 64-slice MDCT.