Scanning pacemaker for ventricular tachycardia.
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Aged↗
Biomedical subjects
C J Havelda
Publications and source records attributed to C J Havelda.
The degree to which myocardial infarct site and size determine the electrocardiographic axis. Analysis of correlative data by computational modeling.
The spatial electrical QRS axis was determined for 428 twelve-lead electrocardiograms from patients subsequently shown by postmortem dissection to have ventricular myocardial fibrosis or necrosis. Four 16-segment ventricular models of the heart were used to "predict" the spatial electrical QRS axis from known ventricular mass and deficit. The raw model I in ideal anatomic position and vectors perpendicularly outward for each muscle segment showed a mean correlation value of -0.494; model II was rotated in the chest to produce best fit with a correlation of 0.638, but the anatomic orientation was not reasonable; model III maintained original position and orientation but the vectors were scaled (correlation 0.780); and model IV, with nonperpendicular vectors, yielded a mean correlation of 0.793. The exceptions to good predictability formed a distinct subset largely composed of electrocardiograms with some form of variant intraventricular conduction (slight QRS widening, fascicular block patterns and "indeterminate frontal-plane axis").
Electrocardiography↗
The pathologic correlates of the electrocardiogram: complete left bundle branch block.
To assess whether gross pathologic differences exist between hearts with left bundle branch block (LBBB) and left-axis deviation (LAXD) and those with LBBB and a normal frontal plane axis, we examined 70 hearts with LBBB in a series of 1410 sequential dissections (5%). Thirty-two hearts had LAXD and 34 had normal axes on the correlative ECG. Left ventricular enlargement occurred frequently (93%). No significant differences were found in age distribution, left ventricular weight, coronary anatomy or infarct location. Quantitative analysis revealed larger inferoposterolateral and apical infarcts in hearts with LBBB and LAXD (p less than 0.01). The accuracy of various electrocardiographic signs of left ventricular enlargement and myocardial infarction in the presence of LBBB was assessed. Voltage criteria and QRS duration poorly define anatomic chamber enlargement. Anterior infarction is suggested by a q or pathological Q wave in lead I, a q wave in leads I, V5 and V6, or notched S waves in V3 or V4. Pathologic q waves or ST shifts in the inferior leads have high diagnostic specificity but low sensitivity for inferior infarction.
Bundle-Branch Block↗
Grand rounds. Limitation of infarct size.
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Animals↗
Relation between right ventricular mass and cavity size: an analysis of 1500 human hearts.
We examined data on the mass, area and myocardial abnormality (scar or infarction) of the right ventricular free wall (RVFW) from 1500 consecutive dissections of hearts that came to autopsy. There were 447 hearts with associated coronary and ischemic heart disease (CAD) and 826 without CAD. RVFW mass was used as an index of hypertrophy (RVH) and RVFW area was used as an index of dilatation (RVD). In both groups of hearts, RVH and RVD were strongly correlated and can be properly referred to as one entity: right ventricular enlargement (RVE). Right ventricular infarction occurred both with and without RVE but rarely without CAD. Right ventricular infarction usually assumed an apical or basal pattern of distribution parallel to that of the adjacent left ventricular lesion.
Electrocardiography↗
Evaluation of lead, zinc, and copper excretion in chronic moonshine drinkers.
To assess the usefulness of various routine and inexpensive tests widely used in the detection of an increased body lead load, the whole blood lead value, the 24-hour urinary excretion of lead, delta-aminolevulinic acid (DALA) and coproporphyrin, the presence of basophilic stippling and the whole blood osmotic fragility test were compared to a 24-hour urinary lead excretion after a calcium disodium edetate (EDTA) mobilization test in 20 chronic moonshine drinkers. Of these tests, only urinary lead excretion after EDTA mobilization was a sensitive indicator of excessive body burden, though a reference value of 650 micrograms urine lead excretion per 24 hours may have excluded some patients with increased lead loads. The reason for increased zinc and copper excretion before and after EDTA mobilization is not known but raises the possibility of their concomitant contamination of moonshine whiskey.
Alcoholic Beverages↗
Irradiation-induced constrictive pericarditis requiring pericardiectomy during pregnancy.
Constrictive pericarditis is a rare but potentially life-threatening complication of pregnancy. This is a case report of irradiation-induced constrictive pericarditis requiring pericardiectomy during pregnancy. It is hoped that our team approach to this particular problem can serve as a model for the management of similar medical and surgical complications of pregnancy.
Adult↗