Matija Horvat

Intravenous amiodarone versus verapamil for acute conversion of paroxysmal atrial fibrillation to sinus rhythm

Abstract Amiodarone and verapamil are well-known antiarrhythmic drugs used for treatment of ventricular and supraventricular arrhythmias. Although verapamil is the drug of choice for control of the atrioventricular node, it has also been reported to terminate atrial fibrillation. 1–3 Amiodarone has been used extensively for drug-refractory ventricular tachycardia but seldom for termination of paroxysmal atrial fibrillation. 4–6 To our knowledge, no comparative study with amiodarone and verapamil has been reported. Because of this, we compared the efficacy of intravenous amiodarone versus verapamil for conversion of paroxysmal atrial fibrillation to sinus rhythm in a single-blind randomized study.

Acute isoniazid neurotoxicity during preventive therapy

Objective: To describe rare side effects of treatment with isoniazid. Design: Descriptive case report. Setting: Medical intensive care unit in a university medical center. Patient: A 14‐yr old previously healthy girl receiving preventive isoniazid therapy who suddenly developed generalized tonic‐clonic seizures and coma. Interventions: Patient was sedated and mechanically ventilated. She also received pyridoxine intravenously. Measurements and Main Results: An isoniazid overdose was not confirmed. Computed tomography of the brain and electroencephalogram revealed nothing abnormal. Seizures gradually disappeared within 2 hrs after sedation and treatment with pyridoxine. The patient was discharged on day 14 without consequences and has been well for 10 mos. No seizures reappeared after isoniazid was discontinued. Conclusions: We caution against possible isoniazid neurotoxicity in healthy individuals using recommended preventive doses.

Cerebral and coronary gas embolism from the inhalation of pressurized helium

ObjectiveInhalation of helium, which produces a change in the voice, is frequently used among young rock singers to improve their performance. DesignA case report. SettingsAdult medical intensive care unit in a university hospital. PatientA 23-yr-old singer, who accidentally inhaled helium from a high pressurized tank without pressure reduction, presented with transient loss of consciousness and chest pain. InterventionsElectrocardiogram, chest radiograph, biochemical and toxicological analyses, echocardiography, coronary angiography were performed. Measurements and Main ResultsAt admission, the patient slowly regained consciousness. An electrocardiogram showed significant ST elevations in leads I, aVL, and V4–V6. The chest radiograph was consistent with pulmonary congestion and pneumomediastinum. The echocardiogram showed normal sized heart chambers with hypokinesis of the left ventricular lateral wall. Ethanol and urine cannabinoids were present in low concentrations, but no presence of opiates, methadone, cocaine, or amphetamines was documented. Troponin T was positive. Elevation of ST segments gradually disappeared within 30 mins, the drowsiness within 10 hrs, and the thoracic pain within 24 hrs. Coronary angiography showed normal coronary arteries. The patient was discharged on day 3 without any symptoms and with normal electrocardiogram and chest radiograph. ConclusionAccidental inhalation of helium under high pressure can cause symptomatic cerebral and coronary artery gas embolism.

Influence of hemodynamic changes on neuroendocrine response in acute heart failure

We studied 15 patients with acute deterioration of chronic left ventricular heart failure. We compared the influence of reduction of ventricular filling pressures with glyceryl trinitrate versus reduction of ventricular filling pressures with diuretics on plasma concentration of epinephrine, norepinephrine, aldosterone and renin activity. Reduction of ventricular filling pressures with glyceryl trinitrate had no influence on plasma concentrations of epinephrine, norepinephrine, aldosterone and renin activity. After reduction of ventricular filling pressures with diuretics plasma concentrations of epinephrine, norepinephrine and aldosterone decreased, while plasma renin activity did not change. We conclude that there is a difference in the influence of reduction of ventricular filling pressures with glyceryl trinitrate versus reduction of ventricular filling pressures with diuretics, on neuroendocrine response in patients with acute deterioration of left ventricular heart failure. Thus some of the neuroendocrine effects of glyceryl trinitrate are likely to be different from those of diuretics, though that they both produce a reduction in left ventricular filling pressure.

Profound circulatory shock following heroin overdose

A 17-year-old previously healthy girl with profound circulatory shock following a heroin overdose is reported. Except for opiates no other substances and specifically no cocaine were found in the blood and urine samples. Even though the mechanism of shock is not completely understood, severe depression of left ventricular contractility seems to be the predominant reason. Acute right heart failure with decreased pulmonary capillary wedge pressure and arterial vasodilatation resulting in maldistribution of cardiac output cannot be ruled out as possible contributing factors. The shock was successfully reversed with volume loading and a high dose of dobutamine. The recovery was uneventful and the patient was discharged with normal cardiac function.