1/141. exercise-induced paroxysmal atrioventricular block during nuclear perfusion stress testing: evidence for transient ischemia of the conduction system.BACKGROUND: Whether tachycardia-dependent paroxysmal AV block, an uncommon complication of exercise stress testing in patients with infranodal conduction disturbances, can result from acute ischemia of the conduction system is still speculative, and is based on post-hoc evidence of right coronary artery disease and abolition of block after coronary angioplasty. methods AND RESULTS: In two patients, from a database of 3000 undergoing nuclear exercise stress testing, transient paroxysmal AV block developed 1-4 minutes after the injection of the radionuclide agent. Nuclear perfusion imaging demonstrated stress-induced ischemia of the posteroseptal segments, which corresponds to the anatomical region of the His bundle, and perfusion recovery in the images obtained at rest. angiography disclosed critical narrowing of the right coronary artery in both cases. CONCLUSION: Nuclear myocardial perfusion imaging provides noninvasive evidence that transient ischemia of the posteroseptal segment, anatomically corresponding to the His bundle, can result in paroxysmal AV block in patients with severe right coronary artery and chronic infranodal conduction disturbances. The demonstration of the underlying pathophysiological mechanism is useful for selecting the most effective treatment strategy.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
2/141. superior vena cava syndrome as a complication of transvenous permanent pacemaker implantation.venous thrombosis induced by a transvenous permanent pacemaker is a common complication. However, superior vena cava (SVC) syndrome caused by pacemaker leads is only occasionally seen and its prevalence has been estimated to be less than 1 in 1000 pacemaker patients. Herein, we report a Taiwanese patient of high grade AV block, who presented with SVC syndrome 2 years after transvenous permanent pacemaker implantation. This case features fibrotic stenosis of the junction of right brachiocephalic trunk and SVC, and an extensive thrombus formation resulting in complete obliteration of the left brachiocephalic vein. The collateral circulation was so delicate that he still could lead a rather normal life, even if anticoagulant therapy proved to be ineffective from an angiographic point of view.- - - - - - - - - - ranking = 0.014736460221436keywords = circulation (Clic here for more details about this article) |
3/141. Pacing lead adhesions after long-term ventricular pacing via the coronary sinus.Left ventricular pacing via the coronary sinus is being increasingly used. There is little data to guide possible lead extractions that might be required in the future. Significant adhesions to the coronary veins were found 12 years after placing a pacing lead in the posterolateral coronary vein in a man with double inlet left ventricle and severe subpulmonary stenosis who had undergone a Fontan operation. The appearances suggest that percutaneous extraction from the proximal coronary sinus may be feasible but that difficulty may be encountered if the lead tip is placed into the distal coronary veins.- - - - - - - - - - ranking = 2.25keywords = coronary (Clic here for more details about this article) |
4/141. radiation-related myocardial injury. Management of two cases.pericardial effusion and trifascicular block developed 5 years following mediastinal irradiation for Hodgkin's disease in a 19-year-old patient. Another 24-year-old patients had an acute myocardial infarction followed by severe angina pectoris 5 years following mediastinal irradiation for the same disease. A pericardial window and a permanent demand pacemaker were used in the first case; an aorto-coronary vein grafting was utilized in the second patient. Both patients responded to treatment and are well. Five other previously reported cases of myocardial injury that occurred 2 months to 8 years following mediastinal irradiation in young patients were reviewed. To our knowledge, successful surgical treatment of this disease entity has not been reported before. Close, long-term follow-up of patients who have received mediastinal irradiation should be helpful in the early recognition and successful management of these serious cardiac complications. The systematic clinical and radiographic surveilance of these patients should be supplemented by a routine 12-lead electrocardiogram.- - - - - - - - - - ranking = 0.25keywords = coronary (Clic here for more details about this article) |
5/141. Prinzmetal's variant angina.Two patients are described with a typical Prinzmetal's variant angina. Both patients were young, active males with angina of recent onset. They experienced angina only at rest and in one patient the angina had a cyclic character appearing only between 4 and 10 a.m. In both patients there was no correlation whatsoever between the angina pectoris and effort, emotion or change in temperature and the angina reacted promptly to nitroglycerine sublingually. The number of attacks and the intensity of the pain were increasing rapidly over a short period of time in both cases. The stenoses in both patients did not exceed 50% of the lumen of the coronary arteries, but coronary surgery has been performed on clinical grounds because both patients were completely disabled and one of them suffered from life-threatening dysrhythmias. For respectively 18 and 6 months after saphenous vein bypass surgery both patients have been symptom-free and able to resume their work. The problems concerning the diagnosis Prinzmetal's variant of angina pectoris are discussed.- - - - - - - - - - ranking = 0.5keywords = coronary (Clic here for more details about this article) |
6/141. Acute occlusion of left internal mammary artery graft during dual-chamber pacemaker implantation.A patient who had undergone bypass surgery 5 yr earlier, including left internal mammary artery (LIMA) grafting to the left anterior descending artery, underwent transvenous dual-chamber permanent pacemaker implantation for persistent advanced atrioventricular block. Intraoperative LIMA graft obstruction occurred, resulting in anterior myocardial infarction that was treated successfully by primary percutaneous transluminal coronary angioplasty and stenting. This is the first report of the occurrence of this complication during pacemaker implantation.- - - - - - - - - - ranking = 0.25keywords = coronary (Clic here for more details about this article) |
7/141. Concealed accessory pathway manifesting clinically only after pacemaker implantation.A 66-year-old man with coronary artery disease and persistent left superior vena cava received a DDDR pacemaker for symptomatic 2:1 heart block. There was no previous history of tachyarrhythmias. Endless loop tachycardia and repetitive nonreentrant ventriculoatrial synchrony occurred afterwards and were triggered by a late coupled atrial premature beat. ECGs suggested a concealed left posterior accessory pathway that was confirmed during electrophysiological study. Effective palliation was achieved with extension of the PVARP and enabling noncompetitive atrial pacing operation.- - - - - - - - - - ranking = 0.25keywords = coronary (Clic here for more details about this article) |
8/141. Coronary arteritis with marked fibrous periarteritis: case report.A case is presented of a 43-year-old man who died suddenly and unexpectedly from cardiac malignant arrhythmia. autopsy revealed isolated coronary arteritis involving primarily the left coronary stem and extending into the proximal half of its anterior descending branch. The most striking feature of the disease was marked fibrous periarteritis. Similar changes were present segmentally in the peripheral third of the right coronary artery, and also as small isolated foci of adventitial fibrosis in the aortic base. With some hesitation, we classify the case as coronary Takayasu's arteritis.- - - - - - - - - - ranking = 1keywords = coronary (Clic here for more details about this article) |
9/141. Single coronary artery with myocardial infarction and AV block.A case of single coronary artery with myocardial infarction was found in a 77-year-old woman. Study of the conductive system in this case did not show any abnormalities that could be correlated with the terminal clinical episode of heart block. In seven anatomically proven cases reported, the single coronary artery arose from the right aortic sinus, which suggests a possible causal relationship to infarction.- - - - - - - - - - ranking = 1.5keywords = coronary (Clic here for more details about this article) |
10/141. Concealed accessory pathway with long conduction times and incremental properties: a case report.Concealed AP with Slow and Incremental Conduction. We report a peculiar form of permanent junctional reciprocating tachycardia that occurs only during daytime and physical activity. ECG obtained during tachycardia showed an unusual progressive shortening of the ventriculoatrial (VA) interval that was maximal at the first complex and shortest at the last one before block occurred, always at the accessory pathway level. This phenomenon has not been previously described and appears to be a reverse type of Wenckebach block. It was observed during salvos of spontaneous tachycardia and could be reproduced by right ventricular pacing. The accessory pathway was ablated successfully at the right posteroseptal region, close to the coronary sinus ostium. After ablation, there was no VA conduction, and tachycardia did not recur during a 9-month follow-up period.- - - - - - - - - - ranking = 0.25keywords = coronary (Clic here for more details about this article) |
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