Evaluation of left ventricular diastolic function in IgE-mediated anaphylaxis in dogs

Anaphylactic shock-associated cardiomyopathy

Acute heart failure in young people may have other etiologies than myocarditis. We report about a twenty-year-old female developing acute heart failure following an anaphylactic reaction after a Prick test. Initially her left ventricular ejection fraction was severely compromised on echocardiography but normalized quickly. We postulated an anaphylactic shock-associated cardiomyopathy due to the close temporal association to an anaphylactic reaction, the presence of hypereosinophilia, and the absence of specific serologic, microbiologic, and immunologic abnormalities. Anaphylactic-associated cardiomyopathy very likely represents a common cause of acute heart failure and should be thought of in young people with known atopy.

Urinary trypsin inhibitor improves peripheral microcirculation and bronchospasm associated with systemic anaphylaxis in rabbits in vivo

Using intravital microscopy of the rabbit ear for quantitative studies of microvascular dynamics, we examined the impact of urinary trypsin inhibitor (UTI), a proteolytic enzyme inhibitor, on microvascular changes during immune complex-mediated anaphylaxis. A total of 50 rabbits, previously sensitized with horse serum, were anesthetized and mechanically ventilated with pentobarbital and isoflurane for the intravital microscopy. Rabbits were then challenged with intravenous injection of horse serum to induce systemic anaphylaxis. One minute after the challenge, each rabbit was randomly assigned to receive saline (group C), 50,000 units x kg(-1) of UTI (group U1), or 150,000 units x kg(-1) (group U2). There were no statistical differences between hemodynamic variables, including heart rate (HR), mean arterial pressure (MAP), and central venous pressure (CVP), among the survivors in each treatment group. Peak inspiratory pressure rose in all three groups but at a much higher rate in group C (P < 0.05). In contrast with the moderate effects of UTI on the above parameters, microscopic evaluation revealed a substantial difference among treatment groups: upon the initiation of anaphylaxis, the arteriole started to reduce in diameter, but UTI prevented vasoconstriction in the arteriole in a dose-dependent manner. Similar results were observed with blood flow velocity. Because flow rate was calculated as the product of blood flow velocity and vascular cross-sectional area proportional to the square of the vessel diameter, these results indicate that UTI preserves microvascular flow rate during anaphylaxis. Rabbit ear microcirculation is highly preserved in the UTI-treated groups during systemic anaphylactic shock.

[Left ventricular diastolic function: physiology, physiopathology, evaluation, therapy, consequences of anesthesia]

With the exception of cardiac surgery, the acute disturbance of the left ventricular diastole occurs mainly in the elderly. Today it represents 30 to 40% of congestive cardiac failures, however with a lower mortality than for acute systolic disturbances. Generally indicated are relaxation anomalies, proto-mesodiastolic mechanism and problems with compliance, an indicator of the pressure/volume diastolic relationship. Invasive techniques remain the standard method. Doppler echocardiography is becoming increasingly important for the assessment of diastolic function. In most cardiopathies, relaxation anomalies occur early, whereas compliance disturbances are mainly associated with advanced cardiac diseases. During anaesthesia, adverse events (auricular fibrillation, hypovolaemia) may worsen a fragile situation. Anaesthetic agents, in particular volatile agents, act on the ventricular diastole. Long-term therapy of diastolic anomalies includes agents amending left ventricular hypertrophy. Emergency therapy has not yet been systematised.