Journal of electrocardiology
-
This article outlines the up-to-date understanding of the molecular basis of primary ventricular arrhythmias. Two disorders have recently been well described at the molecular level, the long QT syndromes and Brugada syndrome, and this article reviews the current scientific knowledge of each disease. A third disorder, arrhythmogenic right ventricular dysplasia, which is on the cusp of understanding, will also be described.
-
Prehospital triage of cardiac patients for bypass from community hospitals to cardiac centers may improve survival. This article determines if electrocardiogram (ECG)-based scoring triage methods (Aldrich MI scoring, QRS distortion, and the TIMI classification) and location of infarct (via 12 lead ECG) are associated with mortality before and after adjusting for age, sex, and race. It is a retrospective study of 291 AMI adult patients transported by ambulance to community hospitals or cardiac centers. ⋯ Patients classified as a "high risk" for AMI per TIMI status were almost 3 times more likely to die than those at "low risk" and reached borderline statistical significance (P = .06) after adjusting for the covariates. Having an anterior infarct, as opposed to an inferior infarct, was significantly associated with death before and after adjusting for the covariates (Unadjusted OR = 2.6, Adjusted OR = 2.8). Properly training emergency medical system professionals in this area may prove useful for identifying higher risk AMI patients in the prehospital setting.
-
A 63-year-old diabetic man was admitted with general fatigue. Electrocardiogram (ECG) on admission showed complete atrioventricular (AV) blockade associated with prominent bifid T waves. The second component of the bifid T waves was distinguished from U waves by the beat-to-beat varying bifidity and the nadir between the two components located at > or = 1 mm above the isoelectric line. ⋯ Hypokalemia (3.6 mEq/L) was noted at admission. Partial restoration of the potassium level (3.9 mEq/L) prior to temporary ventricular demand pacing obscured the bifid T waves and attenuated the QT prolongation and dispersion to some extent (absolute QT interval ranging 520 to 620 ms). It was concluded that marked bradycardia caused by complete AV blockade (ie, a junctional escaped rhythm at a rate of 42 beats/min), hypokalemia, and underlying diabetes mellitus contributed in concert to the QT prolongation and dispersion leading to the prominent bifid T waves.
-
Kornreich identified 6 body surface potential mapping (BSPM) leads outside the standard 12-lead electrocardiographic (ECG) sites for optimal recognition of ST segment elevation (+) and depression (-) during acute ischemia in anterior, inferior, and posterior myocardial zones (A+, A-, I+, I-, P+, P-). No comparison has been made between the 6 selected BSPM leads and 18-lead ECG (12 + V3-5R + V7-9) in detecting acute myocardial ischemia during coronary occlusion. Continuous 18-lead ECG and 6 selected BSPM leads were recorded in 68 patients (77 vessels) undergoing coronary angioplasty during balloon occlusion. ⋯ The 18-lead ECG was also more efficacious for detecting right ventricular ischemia associated with proximal right coronary artery occlusion and for detecting ST segment elevation during left circumflex artery occlusion. Our findings indicate that the 18-lead ECG is the most frequent source of maximally deviated lead and is more efficacious in detecting myocardial ischemia during balloon occlusion than the 6 selected BSPM leads. The 6 selected BSPM leads do not add information above and beyond the 12- or 18-lead ECG, and thus cannot be recommended as optimal sites for continuous ST segment monitoring of patients with acute coronary syndromes.