Left ventricular myocardial injury and syncope due to pulmonary embolism in a soldier: normal coronaries and novel pathologic electrocardiogram signs.

Objective: We present a soldier with a pulmonary embolism presenting with syncope during an ischemic stress test, subsequently found to have normal coronary arteries (CA).

Case: A 49-year-old soldier had 3 months history of exertional chest pain, shortness of breath, syncope, and malaise. He passed out during a stress echocardiogram and had a positive troponin level.

New antiarrhythmic drugs.

While controversy still exists as to the precise indications for the treatment of all forms of ventricular arrhythmia, advances in the number and, more importantly, type of antiarrhythmic drugs can provide the clinician with a rational basis for selecting antiarrhythmic drug therapy. A host of new agents with different pharmacokinetic and electrophysiological actions are now available, and can be compared or contrasted to conventional antiarrhythmic agents such as quinidine, procainamide, disopyramide, lignocaine (lidocaine) and bretylium. This review summarises the electrophysiological, haemodynamic, pharmacokinetic, and efficacy and safety data of mexiletine, tocainide, flecainide, encainide, propafenone, amiodarone, sotalol, pirmenol, cibenzoline (cifenline) and ethmozine (moracizine, moricizine), and aims to provide a basis on which clinicians can compare and contrast these agents and form an algorithm for selection of antiarrhythmic drug therapy in the treatment of patients with ventricular arrhythmias.

Relative prognostic value of rest thallium-201 imaging, radionuclide ventriculography and 24 hour ambulatory electrocardiographic monitoring after acute myocardial infarction.

Rest thallium-201 scintigraphy, radionuclide ventriculography and 24 hour Holter monitoring are acceptable methods to assess myocardial necrosis, performance and electrical instability. This study examined the relative value of the three tests, when obtained a mean of 7 days after acute myocardial infarction, in predicting 1 year mortality in 93 patients. Planar thallium-201 images were obtained in three projections and were scored on a scale of 0 to 4 in 15 segments (normal score = 60).

Efficacy of oral and intravenous indecainide in ventricular arrhythmias.

To evaluate the efficacy of oral and intravenous indecainide, a new class IC antiarrhythmic agent, 3 separate protocols were performed in patients with benign or potentially lethal ventricular arrhythmias. An open-label intravenous trail in 10 patients was conducted using a dose of 1.7 mg/kg/min under constant monitoring.

Antiarrhythmic agents for chronic ventricular arrhythmias.

A vast array of new antiarrhythmic agents have joined the old agents among the clinician's available resources. While treatment of ventricular arrhythmias is completely justifiable for patients with symptoms, their use to prevent sudden cardiac death has not yet been established. Because of their potential risks, the benefit/risk ratio must always be kept in mind.

Effects of beta blockade on systolic and diastolic left ventricular function at rest and during exercise in patients with chronic stable angina pectoris.

This study examined the effects of beta blockade with betaxolol, a cardioselective, lipid-soluble, beta-adrenergic-blocking agent, on rest and exercise systolic and diastolic left ventricular function in 15 patients, aged 40 to 70 years (mean = 52), with chronic stable angina pectoris. Each patient underwent three upright exercise studies at identical workloads; the first was a baseline study, the second was done 3 hours after a single oral dose, and the third was obtained after chronic therapy for 2 weeks. Beta blockade was evident by significant decreases in heart rate, systolic blood pressure, and diastolic blood pressure at rest and during exercise (p less than 0.

Bepridil hydrochloride for treatment of benign or potentially lethal ventricular arrhythmias.

To define the efficacy and safety of a new once-a-day calcium antagonist, bepridil, 21 patients with frequent ventricular premature complexes (VPCs) underwent a 14-day inpatient monitored trial. After Holter monitoring during placebo administration, patients underwent 2 days of a loading dose of bepridil followed by 12 days of bepridil, 400 mg/day. Holter monitoring during therapy showed that 10 patients (48%) had more than a 70% reduction in VPC frequency and 8 of 16 patients (50%) at least a 95% reduction in frequency of nonsustained ventricular tachycardia.

Implications of abnormal right ventricular thallium uptake in acute myocardial infarction.

The correlates of abnormal right ventricular (RV) thallium uptake were examined in 116 patients with documented acute myocardial infarction (AMI) who underwent predischarge thallium-201 scintigraphy at rest, radionuclide angiography and 24-hour ambulatory electrocardiography. The patients were separated into 2 groups: patients group 1 (n = 31) had increased RV thallium uptake and those in group 2 (n = 85) had no such uptake. The 2 groups were comparable in age, type and site of AMI, peak creatine kinase level, systolic blood pressure and heart rate.

Cardiac arrhythmias in the elderly: antiarrhythmic drug treatment.

The frequency of ventricular arrhythmias increases with age. Several factors make elderly people more prone to antiarrhythmic drug toxicity. Familiarity with the changes in the pharmacokinetics and pharmacodynamics of antiarrhythmic agents may reduce or prevent adverse response in this patient population.

Diastolic mitral regurgitation in patients with atrioventricular conduction abnormalities: a common finding by Doppler echocardiography.

M-mode and Doppler echocardiography were performed in 16 patients with first degree atrioventricular (AV) block, 1 patient with second degree (Wenckebach type) and 3 patients with third degree AV block; 20 individuals with a normal PR interval served as control subjects. The time from the onset of the P wave to the mitral valve closure by M-mode and to the end of mitral flow by Doppler echocardiography were obtained. In 20 normal subjects, the P wave to mitral valve closure interval measured 220 +/- 30 ms by M-mode and to the end of mitral flow 225 +/- 29 ms by Doppler technique (p = NS).

Coronary artery cardiomyopathy. Hemodynamic and prognostic implications.

To assess the prevalence and significance of left ventricular dilatation in patients with severe left ventricular dysfunction secondary to coronary artery disease (or coronary artery cardiomyopathy), we studied 70 patients with an ejection fraction of 35 percent or less and one-vessel coronary artery disease (n = 14) or with multivessel coronary artery disease (n = 56). None had had a recent myocardial infarction or valvular heart disease. Patients who underwent myocardial revascularization during follow-up were excluded.

Electrocardiographic diagnosis of posterior myocardial infarction revisited: a new approach using a multivariate discriminant analysis and thallium-201 myocardial scintigraphy.

This study examined the feasibility of using a multivariate discriminant analysis to design a useful electrocardiographic (ECG) model to diagnose posterior myocardial infarction (MI). Thallium-20) scintigraphy was used as a reference standard to identify posterior scar (fixed perfusion defects). The model was derived from 111 patients of whom 37 had fixed posterior defects and 74 had normal images, and its validity was subsequently tested in a separate group of 180 patients.

Oral antiarrhythmic agents for ventricular arrhythmias.

Ventricular tachyarrhythmia is the most common terminal event causing sudden cardiac death. Risk stratification using 24-hour Holter monitoring to identify ventricular ectopy and noninvasive techniques to detect abnormal left ventricular function is becoming routine. Many cardiologists treat patients with potentially lethal ventricular arrhythmias even though it is unknown as yet whether sudden cardiac death can be prevented.

Effect of collateral vessels on prognosis in patients with one vessel coronary artery disease.

The prognostic implications of coronary collateral channels were examined in 359 medically treated patients with one vessel coronary artery disease and a normal left ventricular ejection fraction (greater than or equal to 50%). There were 149 patients with isolated left anterior descending coronary artery disease (group I) and 210 patients with isolated left circumflex or right coronary artery disease (group II). Collateral channels were present in 68 patients (46%) in group I and 115 patients (55%) in group II.

A review of the uses and limitations of tocainide--a class IB antiarrhythmic agent.

In conclusion, it appears that tocainide will be an extremely important new antiarrhythmic agent in the armamentarium of the clinical cardiologist (Table V). Its similarity to lidocaine and the predictability of its efficacy in patients responsive to lidocaine is an important note. Its lack of interaction with beta blockers and digoxin is also a promising feature.

Forward ejection fraction: a new index of left ventricular function in mitral regurgitation.

Previous studies have shown that a normal LVEF is not a reliable index of LV function in MR. We hypothesized that the forward EF, which is the forward stroke volume (measured by Fick or thermodilution) divided by end-diastolic volume (measured by contrast ventriculography) may be a useful index of LV function, since it represents LV emptying into the aorta. This index was examined in 54 patients with chronic MR who had normal EF (greater than or equal to 50%).

Left ventricular dilatation. Prognostic value in severe left ventricular dysfunction secondary to coronary artery disease.

This study determines the noninvasive prognostic predictors (using radionuclide angiography) in patients with severe left ventricular dysfunction (resting ejection fraction less than or equal to 35 percent) secondary to coronary artery disease. We retrospectively evaluated 94 such patients using rest and exercise radionuclide ventriculography. At a mean follow-up of 16 months, cardiac events occurred in 22 patients: ten patients died of cardiac causes, five patients sustained nonfatal myocardial infarction, and seven patients developed severe congestive heart failure (class 4).