The von Willebrand factor in myocardial infarction and unstable angina: a kinetic study.

Recent studies have demonstrated elevations of von Willebrand Factor following acute myocardial infarction (AMI). In order to determine if this parameter may serve as a marker for AMI, we tested the blood levels of vWF and Factor VIII:C in 28 patients with AMI, 9 patients with unstable angina, 7 patients with atypical chest pain, and 25 healthy volunteers. The level of ristocetin cofactor activity of vWF was between 70 and 144% in the control group. In patients with AMI, the mean level of this activity was 175% on the first day following infarction, rose to a peak of 270% on the fifth and sixth days, and was still significantly greater than normal in all patients on the 14th day. The vWF:Ag level closely paralleled the rise of ristocetin cofactor activity of vWF, with a peak of 336% on day 5. FVIII:C was not significantly changed. No significant elevation of vWF was observed in patients with unstable angina. The ristocetin cofactor activity of vWF and vWF:Ag thus are sensitive biochemical indicators for recent AMI, and may serve as useful markers for up to 14 days following infarction, when the traditional enzymes have returned to normal levels.

Polymorphous ventricular tachycardia in acute myocardial infarction.

Polymorphous ventricular tachycardia (VT) is thought to be uncommon in acute coronary heart disease, but its prevalence has not been determined. Seven hundred seventy-one consecutive patients admitted with acute myocardial infarction (MI) were reviewed for the occurrence of this arrhythmia. Nine patients (1.2%) had polymorphous VT. No patient had any of the predisposing factors previously associated with polymorphous VT. The arrhythmia was resistant to multiple drugs, and repeated cardioversion was effective in only 3 patients. Overdrive pacing was ineffective in the 3 patients in whom it was attempted. Verapamil was effective in 3 of 4 patients in whom it was tried. Six patients with polymorphous VT died during hospitalization; the remaining 3 died within 6 months of discharge. It is concluded that, when compared with regular VT, polymorphous VT in MI carries a poor prognosis. When the arrhythmia occurs in the context of acute ischemia, it appears to be more difficult to treat compared with its occurrence due to other predisposing factors. Verapamil, not usually indicated for ventricular arrhythmias, should be tested in a therapeutic trial.

Atrioventricular block complicating dissecting aneurysm of the aorta.

A 67-year-old patient who presented with acute dissecting aneurysm of the aorta was complicated by progressive transient atrioventricular heart block. Post-mortem examination findings confirmed the diagnosis of dissection of the ascending aorta and revealed an interatrial haemorrhage in the area of the septal atrioventricular junction.

Idiopathic recurrent sustained parasystolic ventricular tachycardia responsive to verapamil in a 15-year-old patient.

A 15-year-old patient is presented with parasystolic ventricular tachycardia which was responsive to oral verapamil. We emphasize the value of verapamil in the treatment of this uncommon arrhythmia.

Torsade de pointes complicating atrioventricular block: report of two cases.

One patient with complete atrioventricular heart block and another with high-degree atrioventricular block, complicated by "torsade de pointes" are presented. Both patients were symptomatic. One had a syncopal episode and the other presented with signs and symptoms of congestive heart failure. The electrocardiographic phenomena of torsade de pointes was repeatedly recorded. No other known predisposing factors for torsade de pointes were identified. The use of right ventricular endocardial pacing suppressed the paroxysms in both patients.