Bilateral Coronary Artery - Pulmonary Artery Fistula with Recurrent Ventricular Tachycardia: Case Report.

INTRODUCTION: Bilateral coronary artery fistulae to pulmonary artery with ventricular tachycardia have not yet been described in the literature. CASE OUTLINE: A case of a 23-year-old male patient who was treated at our clinic for recurrent ventricular tachycardia is presented. The patient was born with six fingers on his left hand, which was surgically corrected in his early childhood. Perfusion scintigraphy demonstrated reversible ischemia at the irrigation zone of the right coronary artery. The coronary angiography revealed two coronary to pulmonary artery fistulae. The right coronary artery fistula drained through a tubular vessel formation into the pulmonary artery, but the left anterior descendent fistula drained via multiple thin tortuous vessels into the pulmonary artery. The right coronary artery fistula was ligated surgically. The control scintigraphy registered no perfusion defect subsequently, but during the procedure ventricular tachycardia occurred. An electrophysiology study followed, but ventricular tachycardia could not be provoked. Two months later ventricular tachycardia occurred again. Two subsequent electrophysiology studies showed no ventricular tachycardia.The patient was treated with an implantable cardioverter defibrillator.Ventricular tachycardia was terminated four times during the first year follow-up. CONCLUSION: The mechanism of the ventricular tachycardia was unclear.The electrophysiology study was not sufficiently reliable in the patient with recurrent ventricular tachycardia and bilateral coronary artery to pulmonary artery fistulae. The therapy of choice and the prevention of sudden death in this case was an implantable cardioverter defibrillator.

[Late stent thrombosis].

INTRODUCTION: Late stent thrombosis is a serious complication after stent implantation and it can lead to the development of acute myocardial infarction or death. A CASE REPORT: A 43-year-old patient was admitted to our clinic to coronary care unit. He was diagnosed with acute ST elevation myocardial reinfarction of inferoposterior localization and with right ventricular myocardial infarction. Eighteen months ago, he had acute myocardial infarction of the same localization, and at the same time, PCI (Percutaneous Coronary Intervention) was performed in acute phase, and two bare metal stents were implanted. Now, the patient had chest discomfort two hours before admittance, and PCI was performed once again in acute phase. The diagnostic coronarography resulted in occlusion of the right coronary artery, on the spot of the previously implanted stents. After the passage of guidewire, the artery was recanalized, and defects of artery opacification, which might have been thrombs, were noticed. The thrombs were seen on the spots of earlier implanted stents and in the posterior inteventricular and posterolateral branches of the right coronary artery. PTCA was performed and the patient received the GP IIb/IIIa antagonist therapy after which the control coronarography showed minimal defects of artery opacification, with good anterograde flow. After complete treatment the patient was in good condition. CONCLUSION: Late stent thrombosis, although not very often, is a very serious complication and can lead to death or acute myocardial infarction. To prevent it, it is necessary that the patient receives dual antiplatelet therapy, and that PCI procedure is performed technically correctly (suitable stent dimensions and proper stent expansion).

[Adenosine stress protocols for myocardial perfusion imaging].

BACKGROUND/AIM: Treadmill test combined with myocardial perfusion scintigraphy (MPS) is a commonly used technique in the assessment of coronary artery disease. There are many patients, however, who may not be able to undergo treadmill test. Such patients would benefit from pharmacological stress procedures combined with MPS. The most commonly used pharmacological agents for cardiac stress are coronary vasodilatators (adenosine, dipyridamol) and catecholamines. Concomitant low-level treadmill exercise with adenosine pharma cologic stress (AdenoEX) during MPS has become commonly used in recent years. A number of studies have demonstrated a beneficial impact of AdenoEX protocol. The aim of the study was, besides introducing into practice the two types of protocols of pharmatological stress test with adenosine, as a preparation for MPS, to compare and monitor the frequency of their side effects to quality, acquisition, as well as to standardize the onset time of acquisition (diagnostic imaging) for both protocols. METHODS: A total of 130 patients underwent pharmacological stress test with adenosine (vasodilatator). In 108 of the patients we performed concomitant exercise (AdenoEX) of low level (50W) by a bicycle ergometar. In 28 of the patients we performed Adenosine ab breviated protocol (AdenoSCAN). Side effects of adenosine were followed and compared between the two kinds of protocols AdenoEX and AdenoSCAN. Also compared were image quality and suggested time of acquisition after the stress test. RESULTS: Numerous side effects were found, but being short lived they did not require any active interventions. The benefit of AdenoEX versus AdenoSCAN included decreased side effects (62% vs 87%), improved safety and patients tolerance, improved target-to-background ratios because of less subdiaphragmatic activity, earlier acquisition, and improved sensitivity. CONCLUSION: The safety and efficacy of adenosine pharmacological stress is even better with concomitant exercise. In the light of these benefits we recommend AdenoEX whenever possible.

[The significance of coronary collateral circulation in the preservation of myocardial function].

INTRODUCTION: After occlusion or subocclusion of the blood vessels, myocardial perfusion is maintained through the collateral vessels. There are two mechanisms of vessel formation: arteriogenesis and angiogenesis. The term arteriogenesis describes the growth of the existing collaterals into mature arteries. On the other hand, angiogenesis, is a process of developing new blood vessels from the preexisting ones. Collateral blood vessels have many functional roles. If they are adequately developed, they can protect the myocardium from ischemic injury. Even when a total occlusion develops, regional left ventricular motility is better in segments with developed collateral circulation. In patients with well-developed collaterals, who experience coronary artery occlusion, often there is no evidence of myocardial infarction in the area of the occluded artery. Well-developed collaterals reduce the risk of unstable cardiac events. CASE REPORT: A case of right coronary artery occlusion with good collateral circulation and preserved myocardial left ventricular motility is presented. After coronary stent implantation, the patient was asymptomatic, and the maximal stress test for myocardial ischemia was negative. CONCLUSION: Despite coronary vessel occlusion, collateral blood flow maintains the pump function of the left ventricle.

[Atypical presentation of right coronary artery occlusion].

INTRODUCTION: Inferior wall myocardial infarctions are usually benign and uncomplicated and rarely result in ventricular disturbances of the heart rhythm. An unusual presentation of an inferior acute myocardial infarction (AMI) with atypical symptoms, and ventricular tachycardia is described. CASE REPORT: A 44-year-old patient was admitted to the coronary care unit (CCU) due to atypical chest pain during exercise and ECG abnormalities in leads L2, L3 and aVF. On admission, ECG could mimic myocarditis, pericardial effusion, left anterior bundle branch block or early repolarization. Two-dimensional echocardiography revealed a hypertrophic myocardium without abnormal regional wall motion, good left ventricular function and ejection fraction of 65%. The presumptive prediction of a culprit artery based on the ECG recorded on admission was conclusive for inferior AMI. Fibrinolytic therapy was started 3 hours after the onset of chest pain. Resolution of ST segment elevation and relief of chest pain occurred within one hour of the infusion. On the fifth day after admission, the patient had a nonsustained ventricular tachycardia (VT) which was resolved with amiodarone. Angiography showed acute occlusion of the mid portion, right coronary artery (RCA) and collateral circulation in the distal portion. DISCUSSION AND CONCLUSION: Malignant ventricular arrhythmias can result from isolated inferior wall AMI, but literature reports on this phenomenon are rather rare. Collateral circulation can prevent myocardial ischemia and preserve myocardial function, but does not provide protection against exercise-induced myocardial ischemia.