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Biomedical subjects

A Geibel

Publications and source records attributed to A Geibel.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Echocardiographic diagnosis of pathologic processes of the central pulmonary vessels].

Diseases of the central pulmonary arteries are difficult to diagnose. Echographic imaging of the pulmonary arteries can best be done using the suprasternal and transesophageal approach. In pulmonary arterial hypertension, the central pulmonary arteries increase in size, a fact that is used echographically to diagnose pulmonary hypertension. Even when there is volume overload (e.g. in congenital heart disease with a left-to-right shunt), characteristic changes of the pulmonary vessels are observed. Thromboemboli within the pulmonary arteries or thrombotic occlusion and a malignant process, which can lead to an obstruction or compression of the central pulmonary arteries, could be seen with echographic imaging techniques.

Arterial Occlusive Diseases↗
PubMed1989

[Ventricular arrhythmia in silent myocardial ischemia--diagnosis and clinical relevance].

Silent myocardial ischemia and ventricular arrhythmias were known to be independent risk factors in patients with coronary artery disease. This has become more important since the technique of Holter monitoring has been improved and has demonstrated a high incidence of silent myocardial ischemia in the majority of patients with coronary artery disease, as well as a close relation to the occurrence of sudden cardiac death. Unfortunately, prospective data on the interaction of both risk factors are missing. We therefore studied patients undergoing exercise-testing, percutaneous transluminal angioplasty and 24-h-Holter-monitoring to assess such an interaction. During exercise testing the total incidence of ventricular arryhthmias in patients with asymptomatic ST segment depression was 42%; 6% of patients had frequent ventricular arrhythmias, 6% had ventricular pairs, and 1% had ventricular tachycardia. The incidence was similar to patients with symptomatic ST depression, but was 3.2-times higher as compared to patients without ST segment depression. During 103 attempts of percutaneous transluminal angioplasty, in 26 patients ventricular arrhythmias occurred, the incidence of ventricular tachycardia was 1-3%. No difference was observed for symptomatic and asymptomatic attempts. In 36 patients with severe coronary stenosis (greater than 90%) 24-h-Holter-monitoring showed 145 episodes of myocardial ischemia with a total duration of 967 min; two-thirds of episodes were asymptomatic. The incidence was similar in patients with symptomatic and asymptomatic episodes of myocardial ischemia, but 30 to 50-times higher as compared to the interval with ischemia. In summary, episodes of myocardial ischemia have a higher risk of ventricular arrhythmias, however, there is no difference between symptomatic and asymptomatic myocardial ischemia.

Arrhythmias, Cardiac↗
PubMed1988

Mode of death in idiopathic dilated cardiomyopathy: a multivariate analysis of prognostic determinants.

A total of 110 patients with idiopathic dilated cardiomyopathy were followed prospectively for 53 +/- 8 (range 41 to 69) months to determine prognostic factors identifying patients at risk for sudden death or death from congestive heart failure. During the follow-up period 39 patients died, 14 of congestive heart failure and 25 suddenly. The incidence of cardiac death after 1 year was 18%, after 2 years 35%, and after 4 years 39%. Multivariate logistic regression analysis identified four independent prognostic factors: left ventricular ejection fraction, cardiac index, number of ventricular pairs/24 hours, and atrial rhythm (sinus rhythm or atrial fibrillation). With the final model of logistic regression 77 of 88 patients (88%) could be classified correctly as being at risk for death from chronic heart failure or sudden cardiac death. Patients who were likely to die of congestive heart failure were characterized by a markedly impaired left ventricular function (measured in terms of left ventricular ejection fraction, cardiac index, or both) and a low number of pairs/24 hours. The association between frequent complex ventricular arrhythmias and depressed left ventricular function identifies patients who are at risk for sudden death. The presence of atrial fibrillation significantly increases the risk of sudden death and death from congestive heart failure.

Adult↗
PubMed1988

Changes in cycle length at the onset of sustained tachycardias--importance for antitachycardiac pacing.

We analyzed changes in the spontaneous cycle length of sustained tachycardia during the first 100 beats after electrophysiologic initiation of sustained monomorphic ventricular tachycardia (VT), atrioventricular nodal tachycardia (AVNT), and circus movement tachycardia incorporating an accessory pathway (CMT). The mean cycle length of VT was 288 +/- 75 msec, for AVNT this value was 388 +/- 63 msec, and for CMT this value was 348 +/- 76 msec. After initiation, in all three types of tachycardia changes in cycle length of up to +/- 15% to 25% were observed. The changes in cycle length ranged from +12% to -18% in patients with VT, from +17% to -15% in patients with AVNT, and from +17% to -15% in patients with CMT. The mean percentage of changes during the first 100 beats of tachycardia was 7.0 +/- 4.7% (VT), 9.5 +/- 5.4% (AVNT) and 8.3 +/- 5.4% (CMT). Patients with VT and AVNT showed both a constant increase or decrease or alteration of the rate of tachycardia. In no patient with CMT was there a constant decrease in cycle length after initiation. The mean time to achieve the maximal increase or decrease in cycle length was 13 +/- 6 and 11 +/- 9 seconds in patients with VT and 16 +/- 3 and 20 +/- 7 seconds in patients with AVNT. In patients with CMT, the mean time to achieve the maximal increase (10 +/- 7 seconds) or decrease (20 +/- 9 seconds) varied markedly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Prediction of efficacy and tolerance of oral mexiletine by intravenous lidocaine application.

In a controlled crossover trial, 15 patients with frequent ventricular arrhythmias were treated with lidocaine to predict efficacy and safety of oral mexiletine. After an initial control period, patients received intravenous lidocaine (bolus infusion of 200 mg/20 min followed by 3.6 gm/24 hr and for 7 days oral mexiletine (200 mg four times a day). Efficacy was controlled by 24-hour Holter monitoring (responders = suppression of single premature ventricular beats [PVB] greater than 84% and of complex PVB greater than 90%). After lidocaine, 10 of 15 patients (67%) were responders (mean PVB reduction: 97%). After mexiletine, five of 15 patients (33%) were responders (mean PVB reduction: 81%); efficacy was closely related to the plasma concentration. When efficacy of both agents was compared, lidocaine infusion had a positive predictive value of only 50%; however, the negative predictive value was 100%. Thus in nonresponders to lidocaine, mexiletine is very likely to fail in the suppression of ventricular ectopy.

Administration, Oral↗
PubMed1988

[Diprafenone--comparative study of anti-arrhythmia therapy with propafenone].

Diprafenone is a new antiarrhythmic agent with a dominant local anesthetic action and additional beta-sympathicolytic activity. In a randomized study, we analyzed the antiarrhythmic efficacy and tolerance of diprafenone (450-600 mg/day) in comparison to that of propafenone (450-500 mg/day) in ten patients with frequent and complex ventricular premature beats. After an initial control period, all patients received either diprafenone 450 mg/day or propafenone 450 mg/day for 5 days. In the case of a drug response (VPB suppression greater than 84%, suppression of ventricular pairs greater than 90%, suppression of ventricular tachycardia greater than 100%), after a wash-out period of 7 days patients were treated with the second antiarrhythmic medication for 5 days. In the case of nonresponsiveness, the dose of diprafenone and propafenone was increased to 600 mg/day and treatment continued for a second 5-day period. During the control period and at every drug administration, 24-h-Holter monitoring and ECG were performed, and plasma concentration and side effects were checked. After individual dose titration, 7/10 cases were effectively treated with diprafenone (mean dose: 471 mg; mean VPB suppression: 92%) and 5/10 cases with propafenone (mean dose: 540 mg; mean VPB suppression: 80%). Altogether four patients reported side effects, mainly gastrointestinal, which limited therapy in one patient in each group. Compared to propafenone, diprafenone had a strong effect on AV-nodal and ventricular conduction intervals; however, in no patient was therapy limited by these changes. Thus, also in comparison to propafenone, diprafenone is effective in the treatment of ventricular arrhythmias.

Aged↗
PubMed1988

[Bepridil--electrophysiologic properties of a new calcium antagonist with an anti-arrhythmia effect].

In 12 patients with recurrent pre-syncope or syncope and suspected sick sinus syndrome, the electrophysiologic properties of bepridil were tested using 1-2 extrastimuli during four basic pacing rates. Bepridil was given in a dose of 5 mg/kg body weight over 10 min. It caused no significant changes in sinus cycle length (+5%) and corrected sinus node recovery time during pacing of 100/min (-6%), 120/min (+8%) and 140/min (+4%). The conduction times PQ- (+10%) and QRS-interval (+6%) increased significantly, AH- (+8%) and HV-interval (+5%) were slightly prolonged. Antegrade Wenckebach point increased from 460 to 508 ms (p less than 0.05). The effective refractory period was prolonged in the atrium (+11%, p less than 0.05), the AV-node (+14%, p less than 0.05) and the right ventricle (6-11% at pacing rates 100-140/min, p less than 0.05 for each cycle length). In relation to the pacing rate, QTc-interval increased highly significantly (p less than 0.01) by 16% (sinus rhythm), 12% (100/min), 20% (120/min) and 19% (140/min). After a mean of 5 min after the start of infusion a doubled T-wave was observed in 11/12 patients, persisting during Holter monitoring for several hours without evidence of increased incidence of spontaneous ventricular arrhythmias. During programmed electrical stimulation with 1-2 extrastimuli, no increase in vulnerability of the right ventricle was obvious in any patient.

Adolescent↗
PubMed1987

Programmed electrical stimulation in healed myocardial infarction using a standardized ventricular stimulation protocol.

The diagnostic accuracy of programmed electrical stimulation was prospectively assessed in 111 patients with myocardial infarction (MI) with or without a history of spontaneous ventricular arrhythmias. In 29 patients neither ventricular tachycardia (VT) nor episodes of 10 premature ventricular depolarizations per hour was documented. Fifty patients had documented nonsustained VT and 32 had sustained monomorphic VT. One and 2 extrastimuli (twice diastolic threshold, 2 ms in duration) were given during sinus rhythm and ventricular pacing at 100, 120 and 140 beats/min in the right ventricular apex (part I). When this protocol failed to induce a sustained monomorphic VT, a third extrastimulus was introduced (part II). Repetitive ventricular responses were induced in all patients, and in 15 (14%) polymorphic ventricular arrhythmias requiring DC shock were induced. Incidence of initiation of sustained monomorphic VT and polymorphic ventricular arrhythmias requiring DC shock was related to the clinical arrhythmia and the stimulation protocol. In patients with documented sustained monomorphic VT, a third extrastimulus only increased the incidence of sustained monomorphic VT (68% to 94%), whereas in patients with documented nonsustained VT and without VT the incidence of both polymorphic and monomorphic arrhythmias increased by 7 to 12%. Sustained monomorphic VTs induced in patients without such a history were faster (p less than 0.01), depended on site of MI (p less than 0.05) and were more often preceded by nonsustained polymorphic VT (p less than 0.01) than in patients with documented sustained monomorphic VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Relation between spontaneous and electrically inducible ventricular arrhythmias in patients with coronary heart disease].

In a prospective study, 267 patients with invasively diagnosed coronary artery disease were studied by programmed electrical stimulation (PES) and induced ventricular arrhythmias were compared to spontaneous arrhythmias occurring during 24 h Holter registration. In 89 patients (33%) no evidence of myocardial infarction was present, 61 patients (23%) were studied for 6 weeks to 3 months, 36 patients (13%) for 3-6 months and 81 patients (31%) for more than 6 months after myocardial infarction. PES was performed in the right ventricular apex with 1 and 2 extrastimuli during pacing with 100, 120 and 140 beats/min. Endpoint of the study was defined by the induction of 4 repetitive ventricular responses (RVR). Within 72 hours after PES a 24 h Holter registration was performed in all patients. During PES, 15 patients (6%) were not inducible for any RVR. Single RVR (1-2) were induced in 146 patients (55%) and 3-5 RVR in 68 patients (25%). Ventricular tachycardia and ventricular fibrillation were induced in 38 patients (14%); 6 patients showed a sustained, monomorphic tachycardia. Altogether, the incidence of RVR was higher when a history of myocardial infarction was present. With increasing time after infarction the incidence of inducible 3-5 RVR remained stable; however, the number of greater than 6 RVR decreased. During Holter registration, 54/255 patients (21%) showed no spontaneous ventricular arrhythmias, 70 patients (28%) had arrhythmias of Lown-class I/II, 84 patients (33%) of Lown-class III. Complex arrhythmias were observed in 47 patients (18%) (Lown-class IVA: 33 patients, IVB: 14 patients).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1987

[Anti-arrhythmia effectiveness and tolerance of retard in comparison with standard mexiletine].

In a controlled randomized cross-over trial, 21 patients with coronary artery disease and frequent ventricular arrhythmias were studied to test the efficacy and tolerance of mexiletine 200 mg t.i.d. in comparison to a released application form of mexiletine perlongettes 360 mg b.i.d. During 24-hour Holter monitoring, all patients but one showed more than 30 ventricular premature beats/h; additionally, in 16 patients, complex ventricular arrhythmias (Lown class IV) were documented. In all patients each medication was given for 5 days. Before treatment and during both medication periods, a 4 days' wash-out period was interposed. Mexiletine and mexiletine perlongettes each resulted in a suppression of ventricular ectopy of more than 84% in 10/21 patients (47%); in two patients the response was different. The mean reduction rate in all patients was 68% for mexiletine and 64% for mexiletine perlongettes. In the responder group, the mean reduction rate amounted to 95% under both medications. Ventricular pairs and tachycardia were reduced by more than 90%. Plasma concentration under mexiletine perlongettes was slightly higher, as compared to the standard form of mexiletine; however, under mexiletine, significant changes of plasma concentration were observed during the day only when the standard form was used. Side effects were observed in 8/21 patients (38% for mexiletine) and in 5/21 patients (24% for mexiletine perlongettes). These were mainly gastrointestinal or neurological, but were mild in all patients and did not necessitate discontinuation of the medication in any patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Relation between hemodynamics and ventricular arrhythmia in patients with heart valve diseases].

The incidence and severity of ventricular arrhythmias were compared with hemodynamic findings of cardiac catheterization, in 160 patients with mitral and aortic valve disease. All patients underwent right and left heart catheterization, as well as M-mode and 2D-echocardiography, and 24-hour ambulatory electrocardiographic monitoring. Out of 160 patients, 68 had mitral valve disease and 92 had aortic valve disease. In mitral regurgitation the degree and frequency of ventricular arrhythmias showed a positive correlation to the degree of regurgitation (rs = 0.44, rs = 0.56, respectively) and a negative correlation to left ventricular ejection fraction (rs = -0.49, rs = -0.57) and to cardiac index (rs = 0.48, rs = 0.53). In aortic valve disease the incidence and severity of ventricular arrhythmias were not related to the type of valve lesion, to the transvalvular pressure gradient nor to the degree of regurgitation. In aortic stenosis, the degree of arrhythmia showed a negative correlation to left ventricular ejection fraction (rs = 0.55) and a positive correlation to left ventricular endsystolic volume index (rs = 0.40) and to peak systolic left ventricular wall stress (rs = 0.59). In aortic regurgitation the number of ventricular arrhythmias showed a negative correlation to left ventricular ejection fraction (rs = -0.43) and a positive correlation to left ventricular endsystolic volume index (rs = 0.43) and to peak systolic left ventricular wall stress (rs = 0.37). These data demonstrate that the incidence and severity of ventricular arrhythmias, in patients with aortic valve disease and mitral regurgitation, are strongly associated with the impairment of left ventricular function.

Adult↗
PubMed1986

Electrophysiologic characteristics of ventricular tachycardia or fibrillation in relation to age of myocardial infarction.

Evaluation of ventricular myocardium after the onset of acute myocardial infarction (AMI) suggests that the substrate for ventricular arrhythmias changes as the substrate for ventricular arrhythmias changes as the AMI heals. To determine if the ability of programmed stimulation to initiate ventricular tachycardia (VT) varies according to the interval between AMI and electrophysiologic testing, the clinical and electrophysiologic data of 42 patients with spontaneous sustained VT and 12 patients with ventricular fibrillation (VF) more than 3 days after a single AMI were analyzed. For patients with VT, there were no significant differences in the incidence of initiation of sustained monomorphic VT among those evaluated 1 to 3 weeks (100%), 3 to 8 weeks (75%), 2 to 6 months (100%), 6 to 18 months (80%) or more than 18 months (81%) after AMI, and the mean number of extrastimuli required for initiation did not differ among the groups. Patients evaluated more than 4 weeks after the initial episode of VT had a lower incidence of inducible VT than those studied earlier (14 of 21 [71%] vs 21 of 21 [100%], p less than 0.05), although this appeared to be a result of earlier termination of the stimulation protocol owing to initiation of polymorphic arrhythmias in those studied later. The 14 patients evaluated within 8 weeks of AMI had significantly faster VT rates (mean cycle length 269 +/- 45 ms) than the 28 patients studied later (320 +/- 75 ms, p less than 0.01), possibly because of more out-of-hospital presentations of VT in patients studied later.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗