David M. Salerno

Efficacy and safety of intravenous diltiazem for treatment of atrial fibrillation and atrial flutter

This study evaluates the effectiveness and safety of intravenous diltiazem for the treatment of atrial fibrillation and atrial flutter. A double-blind, parallel, randomized, placebo-controlled protocol was used, and 6 large, urban hospitals, both university-affiliated and private, participated. The study involved 113 patients with atrial fibrillation or flutter, a ventricular rate greater than or equal to 120 beats/min and systolic blood pressure greater than or equal to 90 mm Hg without severe heart failure. The dose of intravenous diltiazem (or identical placebo) was 0.25 mg/kg/2 minutes followed 15 minutes later by 0.35 mg/kg/2 minutes if the first dose was tolerated but ineffective. If a patient did not respond, the code was broken and the patient was allowed to receive open-label diltiazem if placebo had been given. Of 56 patients, 42 (75%) randomized to receive diltiazem responded to 0.25 mg/kg and 10 of 14 responded to 0.35 mg/kg, for a total response rate of 52 of 56 patients (93%), whereas 7 of 57 patients (12%) responded to placebo (p less than 0.001). After the double-blind protocol, 49 of the 57 patients who received placebo were then given diltiazem; 47 of 49 responded, for an overall response rate of 99 of 105 patients (94%) with diltiazem. The median time from the start of drug infusion to the maximal decrease in heart rate was 4.3 minutes. Side effects occurred in 14 patients, 7 of whom had asymptomatic hypotension not requiring intervention. Thus, intravenous diltiazem was rapidly effective for slowing the ventricular response in most patients with atrial fibrillation or atrial flutter. Blood pressure decreased slightly. Side effects were mild.

Effectiveness and costs of digoxin treatment for atrial fibrillation and flutter.

Clinical outcomes and costs associated with the use of digoxin in atrial fibrillation and flutter were evaluated in a prospective, observational study at 18 academic medical centers in the United States. Data were collected on 115 patients (aged > 18 years) with atrial fibrillation or flutter who were treated with digoxin for rapid ventricular rate (> or = 120 beats/min). The median time to ventricular rate control (i.e., resting ventricular rate < 100 beats/min, decrease in ventricular rate of > 20%, or sinus rhythm) was 11.6 hours from the first dose of digoxin for all evaluable patients (n = 105) and 9.5 hours for those only receiving digoxin (n = 64). Before ventricular rate control, the mean +/- SD dose of digoxin administered was 0.80 +/- 0.74 mg, and a mean of 1.4 +/- 1.8 serum digoxin concentrations were ordered per patient. Concomitant beta-blocker or calcium antagonist therapy was instituted in 47 patients (41%); in 19 of these, combination therapy was initiated within 2 hours. Adenosine was administered to 13 patients (11%). Patients spent a median of 4 days (range 1 to 25) in the hospital; 28% spent time in a coronary/intensive care unit and 79% in a telemetry bed. Loss of control (i.e., resting ventricular rate returned to > 120 beats/min) occurred at least once in 50% of patients and was associated with a longer hospital stay (p < 0.05). Based on 1991 data, the estimated mean hospital bed cost for patients with atrial fibrillation or flutter was

Prevalence, characteristics and significance of ventricular premature complexes and ventricular tachycardia detected by 24-hour continuous electrocardiographic recording in the Cardiac Arrhythmia Suppression Trial

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Seismocardiography: a technique for recording precordial acceleration

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Intravenous Verapamil for Treatment of Multifocal Atrial Tachycardia with and without Calcium Pretreatment

Abstract The prevalence, characteristics and significance of ventricular arrhythmias detected by ambulatory electrocardiography were evaluated in 1,498 patients who were randomized to encainide, flecainide or placebo in the Cardiac Arrhythmia Suppression Trial. The mean ventricular premature complex (VPC) frequency at baseline was 133 ± 257 VPCs/hour. Nonsustained ventricular tachycardia (VT) (rate ≥120 beats/min) was present in 22% of patients. Accelerated idioventricular rhythm (rate Thus, in the Cardiac Arrhythmia Suppression Trial the previously described association between mortality/resuscitated cardiac arrest and ventricular arrhythmias (VPC and VT) were only observed in the active treatment group. In addition, based on the results obtained in this highly selected population, it is suggested that the definition of accelerated idioventricular rhythm should be a rate

Effect of hypertonic sodium bicarbonate on encainide overdose

The methodology for obtaining a recording and the initial findings from the seismocardiography (SCG) technique are described. It is shown that the seismocardiogram contains clearly defined points associated with the cardiac cycle that are correlated by analyzing simultaneous SCG and M-mode and Doppler echocardiograms. In the absence of heart disease, the resting seismocardiogram remains stable over a period of at least three months. There is a recognizable normal seismocardiogram that is altered by chronic left ventricular dysfunction, including myocardial infarction and dilated cardiomyopathy. Ventricular pacing produces reversible changes in the ventricular systolic wave component of the seismocardiogram. Thus, the normal seismocardiogram remains stable over time, but becomes altered during both chronic irreversible and acute reversible changes in left ventricular contraction.<<ETX>>

Postresuscitation Hypokalemia in a Patient with a Normal Prearrest Serum Potassium Level

Verapamil was given to 16 consecutive patients with multifocal atrial tachycardia. Intravenous verapamil was administered at a rate of up to 1 mg/min while heart rate and systolic blood pressure were being monitored. The final 5 patients received 1 g of intravenous calcium gluconate 5 minutes before treatment with verapamil; the first 11 received no calcium. The mean +/- SD heart rate decreased by 21% from 129 to 101 beats/min, a difference of 28, 95% confidence interval (CI), 18 to 38 (p less than 0.0005 by t-test), after a mean of 22 +/- 13 minutes from the start of verapamil administration. The mean verapamil dose was 17 +/- 7 mg (6 to 30 mg). Sinus rhythm was restored in 8 patients. Pretreatment with calcium did not block the effect of verapamil on heart rate (27% decrease with calcium compared with 19% decrease without calcium, a difference of 8%, 95% CI, -7 to 23; p = 0.29) but minimized the decrease in systolic pressure (11% decrease with calcium compared with 27% decrease without calcium, a difference of 16%, 95% CI, 7 to 27; p less than 0.01). Verapamil caused transient asymptomatic hypotension in 1 patient. Arterial blood gases were unchanged by verapamil. Thus, verapamil is safe and effective therapy for multifocal atrial tachycardia, consistently slowing the heart rate and often restoring sinus rhythm. Calcium pretreatment may reduce drug-induced hypotension without preventing the antiarrhythmic effect.

Seismocardiography for Monitoring Changes in Left Ventricular Function during Ischemia

Abstract Encainide is an experimental type IC antiarrhythmic agent. Experience with acute encainide toxicity is limited. Two fatal overdoses have occurred but both patients died before reaching the hospital (personal communication, M. Cool, Bristol Myers Co., 3 85 ). We report a case of acute, massive encainide overdose associated with central nervous system and cardiovascular toxicity.

Cardiac compression wave measuring system and method

Excerpt In two separate clinical studies, patients resuscitated from out-of-hospital cardiac arrest had a nearly 50% incidence of hypokalemia when serum potassium was measured in the emergency room...