What is the clinical evidence from this study?

Population: Healthy (n=12). Intervention: Disopyramide vs. Vehicle controls. Primary outcome: Ventricular function and electrocardiographic intervals.

What question did this study set out to answer?

To evaluate the effects of graded oral doses of disopyramide on cardiac electrical conduction and left ventricular mechanical performance in healthy, conscious dogs.

September 1, 1984Journal of Veterinary Pharmacology and Therapeutics

Effects of disopyramide on the electrocardiogram and ventricular function in the unanesthetized dog*

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Key result

Disopyramide at doses of 7.5, 15, or 30 mg/kg produced a significant, dose-dependent reduction in left ventricular function and prolonged electrocardiographic intervals in healthy dogs.

Why the study?

Does disopyramide affect electrocardiogram parameters and ventricular function in healthy, awake dogs?

Key Points

To evaluate the effects of graded oral doses of disopyramide on cardiac electrical conduction and left ventricular mechanical performance in healthy, conscious dogs.
Evaluated 12 healthy, awake dogs assigned either to receive oral disopyramide at 7.5, 15, or 30 mg/kg three times daily (N=6) or vehicle control (N=6).
Recorded non-invasive serial electrocardiograms and echocardiograms during both baseline control and active experimental dosing periods.
Disopyramide produced no significant changes in heart rate, but it prolonged the PQ interval across all doses, the QT interval at 15 and 30 mg/kg, and the QRS complex only at 30 mg/kg.
Left ventricular pre-ejection period (PEP) and the PEP-to-ejection time ratio increased in a dose-dependent manner, whereas left ventricular ejection time shortened only at the 30 mg/kg dose.
Percent shortening fraction significantly declined at 15 and 30 mg/kg, with the PEP-to-ejection time ratio correlating more strongly with disopyramide dose than shortening fraction.

Structured PICO

Does disopyramide affect electrocardiogram parameters and ventricular function in healthy, awake dogs?

Population

12 healthy, awake dogs evaluated for the effects of graded doses of disopyramide on ventricular function and electrocardiograms.

Intervention

Disopyramide 7.5, 15 or 30 mg per kg body weight orally three times per day

Comparator

Vehicle control

Outcome

Electrocardiogram parameters (heart rate, PQ interval, QRS complex, QT interval) and ventricular function via echocardiogram (left ventricular pre-ejection period, left ventricular ejection time, percent shortening fraction, ratio of pre-ejection period to ejection time)surrogate

Disopyramide produces significant dose-dependent reductions in left ventricular function even at therapeutic levels, which can be evaluated non-invasively.

Discussion

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Implication

Warrants caution extrapolating disopyramide effects to clinical canine use; leaves open validation in diseased models or other species.

Cite This Study

Crosby et al. (1984) studied Healthy (n=12). Disopyramide vs. Vehicle controls was evaluated on Ventricular function and electrocardiographic intervals. Disopyramide at doses of 7.5, 15, or 30 mg/kg produced a significant, dose-dependent reduction in left ventricular function and prolonged electrocardiographic intervals in healthy dogs.

synapsesocial.com/papers/6a9b09fa0c2f6aeda050ae38 https://doi.org/10.1111/j.1365-2885.1984.tb00896.x

Topics

Echocardiography

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Effects of disopyramide on the electrocardiogram and ventricular function in the unanesthetized dog*

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Topics

Effects of disopyramide on the electrocardiogram and ventricular function in the unanesthetized dog*

Key Points

Structured PICO

Discussion

Implication

Cite This Study

Also Consider

Topics

Also Consider