Chronic, complete AV block (CAVB) in the dog leads to ventricular hypertrophy, which has been described as an independent risk factor for arrhythmias. In this model, we examined (1) whether the short- and long-term electrical adaptations predispose to acquired torsade de pointes arrhythmias (TdP) and (2) the nature of the structural and functional adaptations involved. We determined (1) endocardial right (RV) and left (LV) ventricular APD, DeltaAPD (LV APD-RV APD), presence of EADs at 0 weeks (acute: AAVB), and CAVB (6 weeks) and inducibility of TdP by pacing and d-sotalol (n=10); (2) steady-state and dynamic LV hemodynamics at 0 and 6 weeks (n=6); (3) plasma neurohumoral levels in time (n=7); (4) structural parameters of the LV and RV of CAVB dogs (n=6) compared with sinus rhythm (SR) dogs (n=6); and (5) expression of ventricular mRNA atrial natriuretic factor (ANF) in CAVB (n=4) and SR (n=4) dogs. Compared with AAVB, CAVB led to nonhomogeneous prolongation of LV and RV APD and different sensitivity for d-sotalol, leading to EADs (4 of 14 versus 9 of 18, P<0.05), increased DeltaAPD (45+/-30 versus 125+/-60 ms, P<0.05), and induction of TdP in most dogs (0% versus 60%, P<0.05). CAVB led to biventricular hypertrophy, whereas LV ...Continue Reading
Canine left ventricular hypertrophy predisposes to ventricular tachycardia induction by phase 2 early afterdepolarizations after administration of BAY K 8644
Spontaneous and inducible ventricular arrhythmias in a canine model of chronic heart failure: relation to haemodynamics and sympathoadrenergic activation
Abnormalities in intracellular calcium regulation and contractile function in myocardium from dogs with pacing-induced heart failure
Bradycardia-induced abnormal QT prolongation in patients with complete atrioventricular block with torsades de pointes
Hemodynamic, left ventricular structural and hormonal changes after discrete myocardial damage in the dog
Impact of left ventricular hypertrophy on ventricular arrhythmias in the absence of coronary artery disease
Alterations in serum sodium in relation to atrial natriuretic factor and other neuroendocrine variables in experimental pacing-induced heart failure
Determination of catecholamines in human plasma by high-performance liquid chromatography: comparison between a new method with fluorescence detection and an established method with electrochemical detection.
Hemodynamic changes and renal plasma flow in early heart failure: implications for renin, aldosterone, norepinephrine, atrial natriuretic peptide and prostacyclin
A sensitive radioimmunoassay of atrial natriuretic peptide in human plasma, using a tracer with an immobilized glycouril agent
Electrophysiologic consequences of chronic experimentally induced left ventricular pressure overload
Effects of chronic angiotensin I-converting enzyme inhibition on the relations between ventricular action potential changes and myocardial hypertrophy in aging rats
Electrophysiologic characteristics of cells spanning the left ventricular wall of human heart: evidence for presence of M cells
Clinical relevance of cardiac arrhythmias generated by afterdepolarizations. Role of M cells in the generation of U waves, triggered activity and torsade de pointes
Role of interventricular dispersion of repolarization in acquired torsade-de-pointes arrhythmias: reversal by magnesium
Efficacy and safety of d,l-sotalol in patients with ventricular tachycardia and in survivors of cardiac arrest
Further observations to elucidate the role of interventricular dispersion of repolarization and early afterdepolarizations in the genesis of acquired torsade de pointes arrhythmias: a comparison between almokalant and d-sotalol using the dog as its own control
Sudden cardiac death in dogs with remodeled hearts is associated with larger beat-to-beat variability of repolarization
End-diastolic myofiber stress and ejection strain increase with ventricular volume overload--Serial in-vivo analyses in dogs with complete atrioventricular block
Regional differences in the dynamics of refractoriness in intact and hypertrophied in situ canine hearts
Electrophysiological and proarrhythmic parameters in transmural canine left-ventricular needle biopsies
Possible mechanisms of sudden cardiac death in top athletes: a basic cardiac electrophysiological point of view.
In vivo experimental approach for the risk assessment of fluoroquinolone antibacterial agents-induced long QT syndrome
Azimilide and dofetilide produce similar electrophysiological and proarrhythmic effects in a canine model of Torsade de Pointes arrhythmias
Famotidine does not induce long QT syndrome: experimental evidence from in vitro and in vivo test systems
Heart block, ventricular tachycardia, and sudden death in ACE2 transgenic mice with downregulated connexins
Electrophysiologic parameters and predisposing factors in the generation of drug-induced Torsade de Pointes arrhythmias
Sympathetic stimulation produces a greater increase in both transmural and spatial dispersion of repolarization in LQT1 than LQT2 forms of congenital long QT syndrome
Differential effects of beta-blockade on dispersion of repolarization in the absence and presence of sympathetic stimulation between the LQT1 and LQT2 forms of congenital long QT syndrome
The assessment of potential for QT interval prolongation with new pharmaceuticals: impact on drug development
Biological pacemaker engineered by nonviral gene transfer in a mouse model of complete atrioventricular block
In vivo measurement of QT prolongation, dispersion and arrhythmogenesis: application to the preclinical cardiovascular safety pharmacology of a new chemical entity
Protein kinase A activity at the endoplasmic reticulum surface is responsible for augmentation of human ether-a-go-go-related gene product (HERG).
Acute canine model for drug-induced Torsades de Pointes in drug safety evaluation-influences of anesthesia and validation with quinidine and astemizole
Evaluation of the acute electrophysiologic effects of intravenous dronedarone, an amiodarone-like agent, with special emphasis on ventricular repolarization and acquired torsade de pointes arrhythmias
Electropharmacological and proarrhythmic effects of a class III antiarrhythmic drug nifekalant hydrochloride assessed using the in vivo canine models
Role of autonomic nervous activity in the antiarrhythmic effects of magnesium sulfate in a canine model of polymorphic ventricular tachyarrhythmia associated with prolonged QT interval
Rate dependent effects of procainamide on the threshold current for pacing in the setting of postrepolarization refractoriness in dogs
High uniformity of left and right ventricular repolarization dynamics induced by an abrupt decrease in pacing cycle length in a dog is not affected by left ventricular ischemia
Paraplegia increased cardiac NGF content, sympathetic tonus, and the susceptibility to ischemia-induced ventricular tachycardia in conscious rats.
Effect of nonuniform muscle contraction on sustainability and frequency of triggered arrhythmias in rat cardiac muscle.
Comparison of the in vivo electrophysiological and proarrhythmic effects of amiodarone with those of a selective class III drug, sematilide, using a canine chronic atrioventricular block model
Electrophysiological, anatomical and histological remodeling of the heart to AV block enhances susceptibility to arrhythmogenic effects of QT-prolonging drugs
Effects of a typical I(Kr) channel blocker sematilide on the relationship between ventricular repolarization, refractoriness and onset of torsades de pointes
Increased short-term variability of the QT interval in professional soccer players: possible implications for arrhythmia prediction.
ECG marker of adverse electrical remodeling post-myocardial infarction predicts outcomes in MADIT II study
MicroRNA-1 downregulation increases connexin 43 displacement and induces ventricular tachyarrhythmias in rodent hypertrophic hearts
Signalment, clinical signs, and prognostic indicators associated with high-grade second- or third-degree atrioventricular block in dogs: 124 cases (January 1, 1997-December 31, 1997)
Electrophysiological effects of cetirizine, astemizole and D-sotalol in a canine model of long QT syndrome
Electrocardiographic interventricular dispersion of repolarization during autonomic adaptation in LQT1 subtype of long QT syndrome
Window Ca2+ current and its modulation by Ca2+ release in hypertrophied cardiac myocytes from dogs with chronic atrioventricular block
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