Autosomal dominant inheritance of sinus node disease

A family with sinus node disease is presented. The mother was severely affected by sinus bradycardia and required a permanent atrial pacing system. The father is asymptomatic and has no evidence of conduction disturbances. All their offspring (one son and two daughters) are affected with variable degrees of severity. The occurrence of the disease in this family is suggestive of autosomal dominant inheritance with variable penetrance.

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.

Ruptured mitral chordae tendineae may be a frequent and insignificant complication in the mitral valve prolapse syndrome

In this study, we performed 512 echocardiographic studies on 264 consecutive unselected patients with the idiopathic mitral valve prolapse syndrome. Twenty-eight patients (10.6%) had evidence of ruptured chordae tendineae of the mitral valve on M-mode examination and in 24 the diagnosis was confirmed by two-dimensional echocardiography. Mild to severe mitral insufficiency was proven in all of them by left ventriculography during cardiac catheterization. Eight patients underwent surgery to relieve symptomatic severe mitral regurgitation. At operation all had myxomatous degeneration of the mitral valve, two patients were found to have rupture of anterior mitral chordae, and six had rupture of posterior mitral chordae. Twenty (71%) patients with chordal rupture had either mild symptoms or were completely asymptomatic. It is concluded that chordal rupture in patients with the mitral valve prolapse syndrome may be present in asymptomatic patients and go undetected clinically in a substantial number of patients unless a high index of suspicion is maintained. Serial M-mode and two-dimensional echocardiographic studies are of importance in identifying the progression of prolapse findings and may reveal the natural history of this pathologic condition in asymptomatic patients.

Transient electromechanical dissociation in hypertrophic cardiomyopathy

We describe a patient with hypertrophic cardiomyopathy who experienced several episodes of syncopal attacks, in whom the mechanism was transient electromechanical dissociation.

Swallowing induced atrial tachycardia and fibrillation in a patient with a Wolf-Parkinson-White syndrome

A 56-year-old man with the Wolf-Parkinson-White (WPW) syndrome (type A) is described. His presenting signs were paroxysmal atrial tachycardia and fibrillation induced by swallowing. This supraventricular tachyarrhythmia (SVT) could be abolished by performing the valsalva maneuver or carotid stimulation, and prevented only by treatment with amiodarone.

Sinus node dysfunction in a healthy pediatric population

ECG recordings of 624 healthy children (age range 6 to 12 years) from a rural population were analyzed for evidence of sinus node dysfunction. Twelve children were found to have the disorder and they underwent further assessment in order to establish any etiological factors or anatomical abnormalities. All the children were asymptomatic and physical examination was completely normal. Standard ECG taken during 24-h monitoring demonstrated that the most common finding, seen in 10 of 12 patients, was that of sinus arrest. Second-degree sinoatrial exit block, Mobitz type I, occurred in four children and Mobitz type II was seen in three. Two of the children were found to have holosystolic mitral valve prolapse, which was in the normal frequency range for a population of healthy children. After a 2-year follow-up and reassessment, there was no change in the symptomatology, the ECG tracings or the physical findings of any of the children.

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.

M-mode and two-dimensional contrast echocardiography in adult patients with atrial septal defects

M-mode and two-dimensional echocardiographic studies, with and without contrast injection, were performed in 14 adult patients with clinical and radiological signs of atrial septal defects. Two-dimensional contrast echocardiography was found to be the most sensitive technique, allowing a definitive diagnosis to be made noninvasively in 12 patients (86%) of those patients studied. M-mode contrast echocardiography demonstrated an atrial shunt in 6 patients (43%). Regular two-dimensional echocardiography produced a high proportion of false-positive and false-negative results, while the findings on M-mode echocardiography are sensitive but nonspecific. All 14 patients described had the diagnosis confirmed on cardiac catheterization. Performance of the Valsalva maneuver during contrast echocardiography was found to be diagnostically unhelpful. The findings suggest that contrast echocardiography, particularly two-dimensional, is an effective, noninvasive diagnostic technique to be applied on clinical suspicion of atrial septal defects.

Endogenous cortisol and thyroid hormone levels in patients with acute myocardial infarction

Thyroid hormones and cortisol levels were serially measured over seven mornings and evenings in 23 consecutive patients with acute myocardial infarction (AMI) or acute coronary insufficiency (ACI). The patients were divided into two groups, high level cortisol (HLC) and low level cortisol (LLC) groups, according to mean morning and evening cortisol levels. The transient increase in plasma rT3, decrease in T3 and TSH was significantly greater in the HLC group. A diurnal variation in cortisol levels was observed in the LLC group 48 h and in the HLC group 72 h after admission. Taking the 23 patients together, no significant correlation was observed between infarct size (peak CPK levels) and the altered rT3, T4 or TSH levels. However, a significant correlation was obtained between the maximal change in T3, rT3 or TSH and the mean cortisol levels preceding these alterations, as well as between cortisol levels and infarct size. It is suggested that cortisol rather than infarct size may be the dominant factor involved in the alteration of thyroidal levels in AMI patients.

The prevalence of ruptured chordae tendineae in the mitral valve prolapse syndrome

Echocardiographic studies were performed on 134 consecutive patients with idiopathic mitral valve prolapse syndrome. Fifteen patients (11.2%) were noted to have ruptured chordae tendineae on M-mode examination and in 12 of them the diagnosis was confirmed by bidimensional studies. Only four patients were referred for surgery as a result of severe mitral regurgitation. At operation one patient was found to have rupture of the anterior mitral chorda and the other three had posterior mitral chordal rupture. Eleven patients with chordal rupture had either mild symptoms or were completely asymptomatic. It is concluded that chordal rupture in patients with the mitral valve prolapse syndrome does not always result in severe hemodynamic deterioration and may go undetected unless a high index of suspicion is maintained. Serial echocardiographic studies may reveal the natural history of this condition in asymptomatic patients.

The efficacy of Ajmaline in ventricular arrhythmias after failure of lidocaine therapy in the acute phase of myocardial infarction

Forty-three patients in the acute phase of myocardial infarction who were resistant to conventional doses of lidocaine received Ajmaline intravenously (50 mg bolus followed by constant infusion rate of 1-1.5 mg/min). Dangerous ventricular arrhythmias were abolished in 72% of this group of patients (group A). In the remaining patients (28%), Ajmaline was found to be ineffective (group B). There was no reduction of systolic or diastolic blood pressure and there was an insignificant increase in heart rate. Atrio-ventricular or intraventricular conduction defects appeared in 46% of the patients described. There was a statistically significant increase in occurrence of heart blocks in group B patients and among these complete left bundle branch block (CLBBB) was the most prevalent. Atrio-ventricular or intraventricular conduction defects were transient, appearing between 8-36 h (mean 23 h), and were not accompanied by reduction of ventricular rate. Conduction defects disappeared within several hours (up to 24 hours) after Ajmaline was discontinued. It is concluded that Ajmaline administered by this regimen is an effective alternative agent for patients with ventricular arrhythmia not controlled by lidocaine in the acute phase of myocardial infarction.