BACKGROUND: Atrioventricular node (AVN) is an interatrial septum structure located at the apex of triangle of Koch that modulates the transmission of impulses from atria to the ventricles. Vagally mediated AVN block with high frequency stimulation (HFS) was investigated in a few animal and human studies, but prolonged ventricular asystole that was induced by a low frequency proximal Coronary sinus (CS) overdrive pacing has rarely been reported. CASE REPORT: A 40-year-old man was admitted in our hospital for evaluation of syncope and palpitation. He presented with prolonged ventricular asystole by proximal CS pacing during electrophysiological study (EPS). CONCLUSION: There is no comprehensive clinical study to investigate the association of vasovagal syncope with vagally mediated atrioventricular block (AVB) which is induced by posteroseptal area stimulation. Radiofrequency catheter ablation of ganglionated plexi (GP) located close to sinus node and AVN was reported to eliminate the vagal efferent output during vasovagal syncope as a new treatment strategy.

Coronary arteriovenous stulas are rare and may be congenital, traumatic, or iatrogenic. We report one of these rare congenital anomalies with a giant aneurismal right Coronary artery (RCA) in a middle-aged lady who was asymptomatic for a long time.

BACKGROUND: Coronary arteriovenous fistula is a rare congenital or acquired abnormal connection between a Coronary artery and any of the great vessels or any of the heart chambers. Most of them are diagnosed during routine Coronary angiography.CASE REPORT: This case report illustrates a successful surgical ligating of multiple right Coronary artery and circumflex artery fistulas to Coronary sinus.CONCLUSION: According to our experience and literature review, it can be concluded that to prevent potential complications in various cases of Coronary arteriovenous fistula, early surgical management, just after their condition has been diagnosed, is the best choice.

A 55-year-old man referred for cardiac resynchronization therapy (CRT) due to severe heart failure. A severe stenosis in the Coronary sinus vein after the posterior branch disallowed the insertion of the lead. Nevertheless, the stenosis was dilated and the left ventricle (LV) lead was implanted in the lateral marginal branch.

We present a very rare case of partially unroofed Coronary sinus without persistent left superior vena cava in a 74 years old female with a history of hypertension, severe myxomatous bileaflet mitral valve prolapse with severe eccentric mitral regurgitation which was diagnosed during cardiac surgery.

Coronary artery fistula (CAF) is a rare anomaly of the Coronary artery. Patients with this condition are usually asymptomatic. However, cardiac failure may occur later in life due to progressive enlargement of the fistula. Diagnosis is traditionally made by echocardiogram and conventional angiogram. However with the advantage of new technologies such as computed tomography (CT) Coronary angiography, the course and communications of these fistulae can be delineated non-invasively and with greater accuracy. We report a case of a left circumflex artery fistula to the Coronary sinus which was suspected on echocardiogram and the diagnosis was clinched on ECG-gated CT.

A single Coronary artery (SCA) arising from the sinus of Valsalva and supplying the entire heart is a rare congenital anomaly. According to modified Lipton’s classification, L-1 subtype is a most rare type of SCA. We presented a case classified as L-I subtype, in which initially left main divided into the left anterior descending and circumflex arteries normally; then, the second septal artery proceeded as the proximal right Coronary artery, the distal circumflex artery proceeded as the middle and distal right Coronary artery. The patient finally underwent percutaneous intervention in the left anterior descending artery owing to a stable angina.