Heather J. Mathison

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The density of potassium channels, including the inward rectifying current (IK1), the delayed rectifying current and the transient outward current have been reported to be decreased in cardiac hypertrophy. However, it is not known whether the effects of specific ionic channel blockers are altered in this setting. The effects of barium chloride, which(More)
This study tested the hypothesis that combination ion channel blockers of the transient outward current (I(to)) and the rapid component of the delayed rectifying current (I(Kr)) would produce greater prolongation of the ventricular action potential duration (APD) and increased dispersion of the APD in hypertrophied hearts compared with control hearts.(More)
Recent reports of subclinical phonetic deficits in posterior and most particularly in Wernicke's aphasics have challenged the traditional dichotomy which characterized speech deficits in aphasia as anterior/phonetic and posterior/phonological. It is unclear whether the basis of the phonetic deficit in posterior aphasics reflects the fact that the speech(More)
Effects of crystalloid buffer and blood-buffer perfusates on cardiac electrophysiological parameters were compared in four groups of isolated, working rabbit hearts. Hearts were perfused with Krebs-Henseleit buffer or blood plus Krebs-Henseleit buffer (10% hematocrit) over a range of left ventricular afterload (30-100 cmH2O) and cardiac outputs (30-180(More)
Ventricular hypertrophy is associated with several electrophysiologic abnormalities. However, little is known about the pharmacodynamics of antiarrhythmic drugs in the setting of ventricular hypertrophy. We studied the myocardial accumulation and pharmacodynamics of quinidine in 10 control rabbit hearts and 10 with isoproterenol-induced hypertrophy. Hearts(More)
INTRODUCTION Increased dispersion of ventricular repolarization is observed in cardiac hypertrophy and is associated with sudden cardiac death. At present, there is little information about the effects of cardiac hemodynamics and antiarrhythmic drugs on dispersion of repolarization in disease states. We compared the effects of increasing afterload and the(More)
BACKGROUND The fatty acid composition of the phospholipids in sarcolemma may significantly influence cell membrane functions. We evaluated the effects of dietary fat on the pharmacodynamics of the antiarrhythmic drug propafenone in isolated, perfused rabbit hearts. METHODS AND RESULTS Three groups of weanling rabbits (n = 9 each group) were fed diets of(More)
OBJECTIVE Overexpression of calcineurin causes cardiac hypertrophy and arrhythmic deaths. During disease development, sinus bradycardia followed by high degree atrioventricular (AV) block finally culminating in ventricular asystole has been observed over time in calcineurin hearts. AV block is associated with the development of pleomorphic ventricular(More)
We have reported previously that propafenone decreased ventricular excitability and prolonged ventricular conduction time in hearts from rabbits treated with a lard diet compared to those from rabbits treated with a safflower oil diet. We hypothesized that these effects might be modulated by the lipid solubility of the drug. Accordingly, we studied the(More)