Brain injury due to anaphylactic shock: broadening manifestations of Kounis syndrome.

Anaphylactic shock is a real and life threatening medical emergency which is encountered in every field of medicine. The coronary arteries seem to be the primary target of anaphylaxis resulting in the development of Kounis syndrome. Kounis syndrome is a pan-arterial anaphylaxis -associated syndrome affecting patients of any age, involving numerous and continuously increasing causes, with broadening clinical manifestations and covering a wide spectrum of mast cell activation disorders. Recently, Kounis-like syndrome affecting the cerebral arteries was found to be associated with mast cell activation disorders. In anaphylactic shock, the decrease of cerebral blood flow is more than what would be expected from severe arterial hypotension. This is attributed to the early and direct action of anaphylactic mediators on cerebral vessels. While adrenaline is a life saving agent in the treatment of anaphylactic shock, it contains sodium betabisulfite as preservative and should be avoided in sulfite allergic patients. Potential allergens encountered in endodotic practice include formocresol, zinc compounds thiurams, sodium dimethyldithiocarbamade, and mercaptobenzothiazole that might have synergistic action. All these agents together with analgesics, antibiotics, antiseptics, formaldehyde, latex, local anaesthetics and metals used in dental practice, in general, can induce anaphylactic shock. Practitioners should be aware of these consequences. A careful history of previous atopy and reactions is of paramount importance for safe and effective management.

Allergic reactions to local glyceryl trinitrate administration.

To assess the exact cause and extent of transdermal glyceryl trinitrate (GTN)-induced allergic reactions, a study of continuous and intermittent use of GTN patches was conducted in 320 patients with New York Heart Association (NYHA) class II and III angina pectoris. Three commercially available GTN patch systems were used. Twenty-one patients (6.5%) developed cutaneous reactions. In 17 patients (5.3%), the reactions were confined to the area of application and were characterised as irritant reactions. Four patients (1.2%) developed both localised and remote from the area of application lesions and one patient developed a generalised anaphylactic reaction. The rate of discontinuation of therapy was 3.4%. The irritant skin reactions were mainly due to contaminants and additives. Changing to a different transdermal system reduced the incidence of local reactions--a particularly desirable effect in patients who respond well to GTN therapy.

Pregnancy-induced increase of supraventricular arrhythmias in Wolff-Parkinson-White syndrome.

Six women suffering from Wolff-Parkinson-White syndrome and who were previously asymptomatic or nearly asymptomatic, were followed prospectively during and after their subsequent pregnancies. Three women experienced several attacks of supraventricular tachycardia (SVT) for the first time and the rest experienced an increase in their attacks. It seems that there is an increased tendency for SVT in pregnancy. Increased adrenergic sensitivity by estrogens, increased plasma volume, stress, and anxiety during pregnancy may be some of the causative factors.

Left ventricular excursions and velocities during coronary arterial ligation. Effects of nitroglycerin infusion in an experimental model.

To determine the effects of intravenous nitroglycerin on the velocities and excursions of the acutely ischemic myocardium, 20 open-chest dogs were studied by use of ultrasound. In 10 dogs with acute septal ischemia, the posterior wall excursion during contraction (B-C excursion), the mean systolic posterior wall velocity, and the posterior wall excursion remained unaltered. Nitroglycerin, however, increased all these parameters (P less than 0.01). In 10 dogs with acute posterior wall ischemia the B-C excursion (aneurysmal bulging) increased (P less than 0.01), but the mean systolic posterior wall velocity and posterior wall excursion decreased (P less than 0.01). Nitroglycerin increased even more the aneurysmal bulging (P less than 0.01) and the other parameters (P less than 0.01). Increased regional blood flow, reduced afterload, and mechanical pulling of the ischemic myocardium seem to be a possible mechanism. The measurements were obtained using the recently described method of the specific points.

Effects of nitroglycerin on myocardial excursions and velocities in the early hours of acute myocardial infarction.

The effects of sublingual nitroglycerin on septal and left ventricular wall motion were determined by echocardiography in the early hours of acute myocardial infarction (MI) in 20 patients admitted via a mobile coronary care unit. Left ventricular and septal echoes were obtained in 11 patients with acute anterior MI and in 9 with acute inferior MI before and after administration of 500 micrograms sublingual nitroglycerin. In the group with acute anterior MI, nitroglycerin did not significantly affect the B-C excursion, posterior wall excursion, and mean posterior wall velocity. Nitroglycerin significantly increased (P less than 0.01), however, the systolic septal excursion, systolic septal velocity, diastolic septal excursion, and diastolic septal velocity. In the group with acute inferior MI, nitroglycerin significantly increased the B-C excursion (P less than 0.01); posterior wall excursion (P less than 0.01); mean posterior wall velocity (P less than 0.01); systolic septal excursion (P less than 0.01); diastolic septal excursion (P less than 0.05), and diastolic septal velocity (P = 0.01) but did not affect the systolic septal velocity. All measurements were obtained by use of a method of labeling and describing specific points of the wall motion that has been described recently.

Systolic and diastolic septal and posterior wall echocardiographic measurements in normal subjects.

M-mode echocardiographic measurement of septal and left ventricular excursions and velocities was attempted in 109 subjects. Seventy subjects had adequate echocardiograms enabling detailed measurement. Two groups of subjects were studied: a group of normal adults aged nineteen to seventy-eight years and a group of normal juveniles aged nine to eighteen years. The posterior wall excursion (PWE), systolic septal excursion (SSE), diastolic septal excursion (DSE), and diastolic septal velocity (DSV) did not differ in these groups. There were significant differences in the posterior wall excursion during isovolumetric contraction (B-Ce, p less than 0.002), mean posterior wall velocity (PWV mean, p less than 0.002), and systolic septal velocity (SSV, p = 0.05) between the two groups. The measurements were obtained by using the recently published method of the specific points for labeling and description of the wall motion.

Unusual electrocardiographic manifestations in conditions with increased intrathoracic pressure.

Clinical, electrocardiographic and haemodynamic findings of 10 patients suffering from intrathoracic conditions were analyzed. Three patients suffering from left spontaneous pneumothorax, three from large left pleural effusion, three from traumatic rupture of the left diaphragm and one from sliding hiatus hernia were found to have electrocardiographic alternation, while their central venous pressure and pulmonary capillary wedge pressure were increased. With the correction of the condition the electrocardiographic alternation disappeared and the pressures returned to normal. The increase in direct or indirect pressure exerted on the global surface of the heart, as it is reflected in pulmonary capillary and venous pressures, seems to be the cause of the electrical alternation observed in these patients.