Early presentation of dilated cardiomyopathy as a part of seroconversion illness in human immunodeficiency virus infection.

It has been debated whether dilated cardiomyopathy seen in patients with acquired immune deficiency syndrome is caused by the virus itself or by the combination of other factors such as presence of opportunistic pathogens and/or severe immunosuppression. This paper describes the first reported case of a patient with human immunodeficiency virus (HIV) infection presenting with dilated cardiomyopathy during his acute seroconversion illness. Presence of cardiac involvement at a very early stage of HIV infection with no evidence of opportunistic infections, or immunosuppression with high CD4 count indicates that HIV may itself be a cardiac pathogen. This case also illustrates the importance of testing for HIV infection as part of the assessment of any patient presenting with myocarditis or dilated cardiomyopathy.

A prospective study of electrical cardioversion for sustained tachycardias by emergency unit personnel.

Acute symptomatic tachyarrhythmias are commonly seen by emergency unit personnel. Electrical cardioversion is often used at Groote Schuur Hospital to treat such patients because of concerns about the safety and efficacy of intravenous anti-arrhythmic agents. All patients presenting with acute symptomatic tachyarrhythmias who were managed only by the staff of the Emergency Unit were entered into the study to assess the efficacy and safety of direct current (DC) cardioversion. Those with sinus tachycardia or atrial fibrillation of more than 24 hours' duration were excluded. Staff, on joining the unit, were instructed in the use and technique of DC cardioversion, and given simple guidelines for the management of acute tachyarrhythmias. Fifty-three patient events were seen over a period of 16 months: 7 patients had ventricular tachycardia, 21 had atrial flutter, 20 had paroxysmal junctional re-entry tachycardia, 4 had atrial fibrillation and 1 had multifocal atrial tachycardia. Fifty-two were successfully converted to sinus rhythm. One patient with atrial flutter and 9 with paroxysmal junctional re-entry tachycardia reverted after undergoing vagal manoeuvres or receiving intravenous verapamil. Of the remaining 43 patients, 42 (98%) were cardioverted with synchronised DC shock under midazolam sedation (7/7 ventricular tachycardia, 20/20 atrial flutter, 11/11 paroxysmal junctional re-entry tachycardia, 4/4 atrial fibrillation, 0/1 multifocal atrial tachycardia). Four patients had their sedation electively reversed with flumazenil. No complications occurred. DC cardioversion was only considered inappropriate in the 1 patient with multifocal atrial tachycardia. This study shows that if simple guidelines are followed, non-cardiologist junior medical personnel can safely and effectively manage sustained, acute, symptomatic tachyarrhythmias by employing DC cardioversion as and when appropriate.

Substance P level is increased in the cholesterol induced anaphylactoid reaction in the pig.

The role of substance P (SP) in cholesterol-induced anaphylactoid reaction was investigated in 13 Landrace pigs. Pigs were anesthetized with sodium thiopental and ventilation was controlled with 70% nitrous oxide in oxygen. A Swan-Ganz catheter and a carotid arterial line were placed to monitor the hemodynamic data. Group 1 pigs (control group, n = 5) each received 20 ml of intravenous (IV) colloid infusion solution (Haemaccel) and group 2 pigs (cholesterol group, n = 8) each received an IV injection of pure cholesterol emulsion (12 mg/kg) in 20 ml of Haemaccel. Blood samples for SP and histamine (H) levels were taken just before and for 10 min following the placebo, Haemaccel, and cholesterol injections. Urine samples were also collected just before and at 60 min following the injections for methyl histamine (MH) levels. Group 2 pigs (cholesterol) developed an anaphylactoid reaction as indicated by marked and significant hemodynamic changes. None of the group 1 (placebo) pigs developed an anaphylactoid reaction. Significant increases in blood SP and H levels (P < 0.05), and urine MH levels (P < 0.05) were seen in cholesterol-treated pigs (group 2), whereas no significant changes were seen in control pigs (group 1). Our results suggest that SP is involved in the cholesterol-induced anaphylactoid reaction in pigs.

The effect of hepatectomy and plasma cholinesterase inhibition on cocaine metabolism and cardiovascular responses in pigs.

To determine the effects of total hepatectomy and inhibition of plasma cholinesterase activity on cocaine metabolism, we measured plasma concentrations of cocaine and its three major metabolites, benzoylecgonine, ecgonine methyl ester, and norcocaine, by high-performance liquid chromatography in three groups of male pigs. Pigs were anesthetized with sodium thiopental and lungs were ventilated with nitrous oxide in oxygen. A right carotid arterial cannula and an internal jugular venous catheter were then inserted for the administration of cocaine and for blood sampling. A Swan-Ganz catheter was inserted through the right internal jugular vein. Group 1 pigs underwent sham operation; group 2 and 3 pigs underwent hepatectomy and portocaval shunt. In addition, group 3 pigs were treated with tetraisopropyl pyrophosphoramide, a specific plasma cholinesterase inhibitor. After this preparation, pigs were given 4 mg/kg cocaine intravenously over 2 minutes. After cocaine injection, 4 ml blood was collected into heparinized test tubes containing 2.5% sodium fluoride for determination of cocaine and its metabolites at 2, 5, 10, 15, 30, 45, 60, 90, 120, 180, 240, and 300 minutes. We also measured hemodynamic responses after cocaine administration, including heart rate and rhythm, cardiac output, and arterial blood pressure. Data were analyzed by analysis of variance. Blood levels of cocaine and its metabolites were significantly different among the three groups (p < 0.05 by analysis of variance). Our results show that total hepatectomy was associated with a marked slowing of cocaine metabolism, absence of norcocaine, and increased benzoylecgonine levels when compared with the baseline values in the control pigs.(ABSTRACT TRUNCATED AT 250 WORDS)