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Biomedical subjects

D R Düren

Publications and source records attributed to D R Düren.

At least 19 recordsLinked to original sources
PubMed1999

Auditory stimuli as a trigger for arrhythmic events differentiate HERG-related (LQTS2) patients from KVLQT1-related patients (LQTS1).

OBJECTIVE: This study was performed to identify a possible relationship between genotype and phenotype in the congenital familial long QT syndrome (cLQTS). BACKGROUND: The cLQTS, which occurs as an autosomal dominant or recessive trait, is characterized by QT-interval prolongation on the electrocardiogram and torsade de pointes arrhythmias, which may give rise to recurrent syncope or sudden cardiac death. Precipitators for cardiac events are exercise or emotion and occasionally acoustic stimuli. METHODS: The trigger for cardiac events (syncope, documented cardiac arrhythmias, sudden cardiac death) was analyzed in 11 families with a familial LQTS and a determined genotype. RESULTS: The families were subdivided in KVLQT1-related families (LQTS1, n = 5) and HERG (human ether-a-gogo-related gene)-related families (LQTS2, n = 6) based on single-strand conformation polymorphism analysis and sequencing. Whereas exercise-related cardiac events dominate the clinical picture of LQTS1 patients, auditory stimuli as a trigger for arrhythmic events were only seen in LQTS2 patients. CONCLUSIONS: Arrhythmic events triggered by auditory stimuli may differentiate LQTS2 from LQTS1 patients.

Acoustic Stimulation↗
PubMed1997

[Aging and cardiology; various physiological, pathophysiological and clinical aspects].

The main cardiovascular effect of aging is a rise of the systolic blood pressure due to reduced impedance of the central arteries. The resulting increase of the afterload leads to hypertrophy, increased rigidity and lengthening of the relaxation period in the left ventricle. The manifestations of ischaemia or arrhythmias are often atypical at more advanced ages and may delay diagnosis. Ejection murmur due to stenosis of the aortic valve, to calcification or degeneration, may be difficult to distinguish from a functional murmur. The cause of heart failure is usually coronary sclerosis and, less often, hypertension or a valvular defect. Systolic heart failure is associated with decreased contractility of the left ventricle and compensatory dilation, diastolic heart failure with reduced filling of the ventricles. Both forms respond well to acute treatment with antihypertensive, diuretic and (or) vasodilator drugs; the treatment in isolated diastolic heart failure should also focus on lowering the increased blood pressure and reducing the heart rate to increase the filling phase.

Aged↗
PubMed1997

Mitral valve prolapse and ventricular arrhythmias: observations in a patient with a 20-year history.

INTRODUCTION: Ventricular arrhythmias are a common feature in patients with mitral valve prolapse. In an attempt to determine the origin and underlying electrophysiologic mechanism, we describe a patient with ventricular fibrillation, exercise-induced ventricular tachycardia (VT), and, at the time of diagnosis, prolapse of the posterior mitral valve leaflet without mitral regurgitation. METHODS AND RESULTS: Treatment with beta-blockade and diphenylhydantoin prevented the occurrence of malignant ventricular arrhythmias for more than 17 years. Discontinuation of the therapy resulted in an immediate reappearance of the VT, which, despite the marked enlargement of the left ventricle (secondary to development of severe mitral valve regurgitation), had a strikingly similar morphology. For hemodynamic reasons, the patient was finally selected for valve replacement. Detailed pre-, peri-, and postoperative studies were performed, including administration of flunarizine, body surface mapping, construction of perioperative epicardial and endocardial maps, and studies of the excised muscles in vitro. CONCLUSIONS: Delayed afterdepolarization-induced triggered activity is the mechanism of VT in this mitral valve prolapse patient. The trigger is provided by isolated ventricular premature complexes elicited by a different electrophysiologic mechanism, possibly reentry, which is related to stretch and presumably to fibrosis of the papillary muscles.

Adult↗
PubMed1995

[Heart failure in a Ghanese woman due to endomyocardial fibrosis].

Endomyocardial fibrosis was diagnosed in a 30-year-old Ghanese woman suffering from heart failure and intracardial thrombi. Endomyocardial fibrosis is an endemic disease in tropical countries with a high mortality rate. Since the aetiology of this disease is still unknown, patients can only be treated symptomatically. Endocardial and myocardial damage give rise to reactive fibrosis, subendocardial infarction and thrombus formation, resulting in heart failure and thromboembolic processes.

Adult↗
PubMed1995

Long-term antiarrhythmic efficacy and safety of d-sotalol in patients with ventricular tachycardia and a low ejection fraction.

Since in patients with ventricular tachycardia (VT) and compromised left ventricular function, antiarrhythmic therapy poses a particular problem, an open-label safety study of d-sotalol, a new class III antiarrhythmic agent, was performed. Thirteen patients with defined VT and a low left ventricular ejection fraction (LVEF) were treated with orally administered d-sotalol, 100 mg bid, and in a few patients 100 mg tid, in an open study. Patients were followed up for 35 +/- 11 months, with the longest follow-up amounting to 51 months. The data obtained suggest that d-sotalol was moderately effective as an antiarrhythmic agent, in particular with respect to premature ventricular contractions (PVCs) and coupled and repetitive PVCs. The beneficial effect appeared to persist on long-term treatment. d-Sotalol was well tolerated and no subjective or objective adverse reactions were observed. There were no signs of worsening of congestive heart failure, proarrhythmogenic activity, or torsades de pointes, although QT-prolongation was observed. There were no dropouts in the study. Two patients died: One patient with idiopathic dilated cardiomyopathy (with LVEF = 11%) died suddenly after 38 months of follow-up and one patient after 17 months from recurrent myocardial infarction. Neither of these had shown recurrence of VT on 24 hour ambulatory ECG recordings. In conclusion, in this small group of patients d-sotalol appeared to be safe and well tolerated during long-term treatment of patients with VT and poor left ventricular function. There were clear suggestions of antiarrhythmic activity, reflected by the suppression of complex ventricular arrhythmias and by the absence of recurrent VT on long-term follow-up in the majority of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1994

Two cases of amiodarone-induced thyrotoxicosis successfully treated with a short course of antithyroid drugs while amiodarone was continued.

Two patients with amiodarone-induced thyrotoxicosis were treated successfully with potassium perchlorate and carbimazole while treatment with amiodarone was continued. These antithyroid drugs were stopped after the patients had became clinically and biochemically euthyroid. During follow up, when treatment with amiodarone continued, thyrotoxicosis did not recur. Amiodarone-induced thyrotoxicosis seems to be a transient condition that can be treated successfully with a short course of antithyroid drugs without stopping amiodarone treatment.

Adolescent↗
PubMed1993

Effects of changes in management of active infective endocarditis on outcome in a 25-year period.

The clinical outcome and long-term follow-up of 130 consecutive patients (141 episodes) with active infective endocarditis who were treated between 1966 and 1991 were analyzed. There was a shift toward a higher proportion of referred patients (39 to 78%), patients aged > 60 years (11 to 41%) and urgent surgical treatment (11 to 44%). Medical treatment was administered in 98 patients (70%); 30-day mortality was 27%. Surgery was performed in 43 patients (30%), with an operative mortality of 26%; 9 of 14 patients (64%) who underwent operation within the first week of admission died. Patients with severe heart failure are at the highest risk for early mortality (relative risk = 21.1; 95% confidence interval 7.4-60.3). Referred patients were much more often treated surgically than were nonreferred patients (48 versus 14%) and had a lower operative mortality (24 vs 30%). Nonreferred patients were more often treated medically (86 vs 52%) and with lower mortality (19 vs 39%). The total follow-up time was 730 patient-years; only 1 patient was considered lost to follow-up. The overall cumulative 5-year and 10-year survival after hospital discharge for patients after urgent surgery were 84 +/- 7% and 53 +/- 7%, respectively, and for those after medical treatment 84 +/- 5% and 77 +/- 6%, respectively. The probability of remaining free of late events (recurrent endocarditis, late valve replacement or death) during 5 and 10 years for patients after urgent surgery was 84 +/- 7% and 53 +/- 15%, respectively, and for those after medical treatment 59 +/- 6% and 40 +/- 7%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Sarcoidosis of the heart].

In 2 patients arrhythmias and conduction disorders were the first symptoms at presentation of cardiac sarcoidosis. One patient with severe conduction disorders showed normalisation of the EKG during steroid treatment. The other patient developed an overall cardiomyopathy and the arrhythmia was treated with conventional drugs. The frequency of cardiac involvement in sarcoidosis is much higher than that of clinical symptoms of sarcoid heart disease. Cardiac sarcoidosis is increasingly diagnosed in the last few decades. In most cases, it presents with sudden death, arrhythmia, conduction disorders or cardiomyopathy. The main diagnostic pathological feature is evidence of noncaseating granulomas, but mononuclear cell infiltration and focal interstitial fibrosis have also been found. The basal part of the interventricular septum is particularly prone to involvement. If conventional therapy in clinically important cases proves inadequate, steroid therapy should be added. It is recommended to make an EKG in every patient presenting with sarcoidosis even in the absence of cardiac symptoms. Sarcoid heart disease should be considered in every patient with diagnostic sarcoidosis and heart disease but also in every case of difficult heart disease without an obvious aetiology. Because of the relatively early age at onset, life expectancy is shortened.

Adult↗
PubMed1989

[Splenic rupture, sometimes a fatal complication of bacterial endocarditis].

Rupture of the spleen, caused by a septic embolus, developed in a patient, who had been treated for bacterial endocarditis of the aortic valve. The incidence of this rare complication is discussed and the symptoms, diagnosis and treatment are described. The circumstances, under which the diagnosis should be strongly considered, are emphasized.

Adult↗
PubMed1989

Comparison of transthoracic and transesophageal color Doppler flow imaging in patients with mechanical prostheses in the mitral valve position.

This study determined the relative value of transthoracic and transesophageal color Doppler flow imaging to systolic flow patterns in the left atrium in different types of mechanical prostheses in the mitral valve. Thirty-nine patients were investigated. Based on clinical findings, 36 of 39 patients had normal prosthetic valve function. Seventeen patients were interrogated within a few days after surgery. Systolic regurgitant jets in the left atrium were absent in all patients by both transthoracic pulsed and color Doppler flow imaging. Using transthoracic continuous wave Doppler, however, jets were demonstrated in 8 of 39 patients (21%). Transesophageal color Doppler flow imaging demonstrated systolic regurgitant jets originating from the prosthesis in all patients. Tilting disc valves showed jets during the entire systole (closure and leakage backflow). Each type of prosthesis generated a specific jet pattern. Pathologic regurgitant jets were crescent-shaped, more extensive and turbulent than jets caused by normal closure and leakage backflow. Thus, transthoracic color Doppler flow imaging is not sensitive for detecting regurgitant jets in mechanical prostheses in the mitral valve. All mechanical prostheses show a specific jet pattern, which should be helpful when transesophageal echocardiography is used to identify pathologic backflow.

Adult↗