Acute myocardial infarction in a young adult patient with simultaneous total occlusion of double coronary arteries.

We report an otherwise healthy 16-year-old male patient with simultaneous double vessel acute myocardial infarction. Coronary angiography (CAG) showed simultaneous total occlusion of the left anterior descending artery (LAD) and the left circumflex artery (LCX). Emergent percutaneous coronary intervention (PCI) was performed on the diseased lesions. After PCI, coronary artery aneurysms were found in both the LAD and LCX. The patient was discharged after a 56-day hospitalization. The New York Heart Association (NYHA) Functional Classification at discharge was II. Medical therapy became ineffective over time because of exacerbated ischemic mitral regurgitation; successful mitral annuloplasty was performed. The post-operative course was uneventful.

Intramural Purkinje cell network of sheep ventricles as the terminal pathway of conduction system.

To identify the anatomical basis for cardiac electrical signal conduction, particularly seeking the intramural terminals of conduction pathway within the ventricles, sheep hearts were examined compared with human hearts utilizing the characteristic morphology of Purkinje cells as a histological marker. In 15 sheep and five human autopsies of noncardiac death, prevalence of Purkinje or Purkinje-type cells were histologically examined in the atrioventricular node, its distal conduction pathway, the interventricular septum, and the right- and left-ventricular free walls. Myocardial tissue cleavages were examined in the transmural sections (along cardiac base-to-apex axis) obtained from the septum and ventricular free walls. Serial histological sections through virtually the entirety of the septum in selected sheep were used as the basis of a three-dimensional reconstruction of the conduction pathway, particularly of the intramural Purkinje cell network. Purkinje cells were found within the mural myocardium of sheep ventricles whereas no intramural Purkinje-type cell was detected within the human ventricles. In the sheep septum, every intramural Purkinje cell composed a three-dimensional network throughout the mural myocardium, which proximally connected to the subendocardial extension of the bundle branches and distally formed an occasional junction with ordinary working myocytes. The Purkinje-cell network may participate in the ventricular excitation as the terminal conduction pathway. Individual connections among the Purkinje cells contain the links of through-wall orientation which would benefit the signal conduction crossing the architectural barriers by cleavages in sheep hearts. The myocardial architectural changes found in diseased hearts could disrupt the network links including those with transmural orientation. Anat Rec, 2009. (c) 2008 Wiley-Liss, Inc.

Discrimination of Brugada syndrome patients from individuals with the saddle-back type ST-segment elevation using a marker of the standard 12-lead electrocardiography.

BACKGROUND: In the clinical situation, the saddle-back (S-B) type is more frequently detected than the coved type. In the present study, the discrimination of Brugada syndrome from the S-B type individuals using a marker of the standard 12-lead electrocardiography (ECG) was attempted. METHODS AND RESULTS: The study group consisted of 55 individuals with the S-B type in whom pilsicainide provocation test (PLC test) was carried out. The time from the onset of the QRS wave in lead V(2) (IV (2)) to the peak of the late R-like wave in the QRS wave (PV(2)), and the time from IV(2) to the offset of the QRS wave in lead V(5) (EV(5)) were measured. The coved type was induced by the PLC test in 29 cases (N-C group), but not in the remaining 26 cases (N-N group). The (IV(2) -PV(2)) - (IV(2) - EV(5)) value before the PLS test was greater in the N-C group than in the N-N group. The negative predictive value of ;(IV(2) - PV(2)) - (IV(2) - EV(5)) > or =0' was 76.4% for the prediction of a positive PLC test. CONCLUSIONS: A ;(IV(2) - PV(2)) - (IV(2) - EV(5)) > or =0' is a useful ECG marker for the discrimination of Brugada syndrome in the S-B type individuals.

Reversible ventricular dysfunction (takotsubo cardiomyopathy) following polymorphic ventricular tachycardia.

A 67-year-old female with recurrent syncope and no obvious heart disease developed ventricular dysfunction, known as takotsubo cardiomyopathy, following a 90 s episode of polymorphic ventricular tachycardia originating from a ventricular extrasystole with a short coupling interval. Cardiac catheterization performed 30 min after the arrhythmic event revealed angiographically normal coronary arteries, and left ventricular apical akinesis and basal hyperkinesis. An intracoronary injection of acetylcholine revealed no inducible coronary spasm, and an electrophysiological study revealed normal atrioventricular conduction and no inducible ventricular arrhythmia. Thirty hours after the arrhythmic event, electrocardiography revealed deeply inverted T waves in leads V3 to V6, I, and aVL, which continued for more than a week. Although no treatment was given to maintain hemodynamic stability, echocardiography revealed normal left ventricular contraction 14 days after the onset of the ventricular dysfunction. The reversible ventricular dysfunction might have been induced by altered catecholamine dynamics due to the persistent syncope during the occurrence of tachycardia.

Experimental study on the effectiveness and safety of radiofrequency catheter ablation with the cooled ablation system.

Experimental in vitro and in vivo studies were performed to assess the effectiveness and safety of the cooled-tip catheter and the Cooled Ablation System, which enables the creation of deeper and wider burn lesions in the myocardial tissue using radiofrequency current. This system was confirmed to consistently create large burns by cooling the catheter tip with circulating water within the catheter, even under unfavorable conditions. On the other hand, unfavorable effects, as a result of over burning, such as explosive vaporization within the tissue (the 'pop' phenomenon), tissue carbonization, coronary artery injury and lung injury were identified. 'Pop' was difficult to predict, but it is important to know how it can be avoided. No 'Pop' was seen without first observing an impedance decrease, thus it was considered safe to decrease the radiofrequency current if the impedance began to decrease. This system will be very effective for ablation of refractory arrhythmias, such as ventricular tachycardia or atrial flutter, but it is recommended that only experienced electrophysiologists use this system to avoid serious complications.