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Biomedical subjects

W Grimm

Publications and source records attributed to W Grimm.

At least 73 records · Page 4Linked to original sources
PubMed1996

Epicardial neodymium. YAG laser photocoagulation of ventricular tachycardia without ventriculotomy in patients after myocardial infarction.

BACKGROUND: Surgical ablation of ventricular tachycardia (VT) after myocardial infarction has been reported by different endocardial approaches. The ventriculotomy may increase mortality of the procedure. METHODS AND RESULTS: We report on nine patients who suffered from recurrent VT in the late post-myocardial infarction period. Significant stenoses were detected in all patients. The mean left ventricular ejection fraction was 43.1 +/- 8.3%. Left ventricular scar (n = 9) was seen. The mean NYHA class was 2.2 +/- 0.4. Sustained VT (mean cycle length, 293 +/- 52 ms) occurred spontaneously (n = 9) and could be induced reproducibly. Catheter mapping detected a prematurity of -42 +/- 13 ms in six patients. Clinical VT was inducible during surgery in seven patients. Middiastolic potentials were detected from the epicardial surface (n = 3), and premature potentials were found (n = 8 with prematurity of -108 +/- 46 ms). Application of neodymium/yttrium/argon/ garnet (Nd:YAG) laser energy to early epicardial activation terminated the arrhythmia (n = 7). Ventriculotomy was not performed. Seven patients have been free of VT for a mean follow-up period of 17 +/- 11 months; one patient relapsed and was treated with an implantable cardioverter-defibrillator, as was a second patient with inducible VT after surgery. CONCLUSIONS: Surgical Nd:YAG laser photocoagulation of VT on the epicardial surface of the heart in post-myocardial infarction patients without ventriculotomy is safe and has a high success rate. At the present time, this method is recommended in patients with sustained and tolerated VT who need bypass surgery. This is the first report on epicardial laser ablation of VT in post-myocardial infarction VT.

Adult↗
PubMed1996

QT dispersion and arrhythmic events in idiopathic dilated cardiomyopathy.

QT dispersion was measured in the 12-lead standard electrocardiogram in 107 patients with idiopathic dilated cardiomyopathy (IDC) and 100 age- and sex- matched controls without structural heart disease. All 107 study patients with IDC were prospectively followed in order to determine possible associations between QT dispersion and arrhythmic events, i.e., sustained ventricular tachycardia, ventricular fibrillation, or sudden death. QT dispersion, rate-corrected QT dispersion, and adjusted QTc dispersion, which takes account of the number of leads measured, were significantly greater in patients with IDC than in controls. During 13 +/- 7 months follow-up, arrhythmic events occurred in 12 of 107 study patients with IDC (11%). QT dispersion was increased in patients with versus without arrhythmic events during follow-up (76 +/- 17 vs 60 +/- 26 ms; p=0.03). QTc dispersion and adjusted QTc dispersion were not significantly different between patients with and without arrhythmic events (80 +/- 21 vs 75 +/- 35 ms, and 27 +/- 6 vs 24 +/- 10 ms, respectively). Thus, although QT dispersion was increased in patients with IDC and arrhythmic events during follow-up, its usefulness for arrhythmia risk prediction was limited by the large overlap of QT dispersion between patients with and without arrhythmic events.

Anti-Arrhythmia Agents↗
PubMed1996

Electrophysiologic evaluation of sinus node function and atrioventricular conduction in patients with prolonged ventricular asystole during obstructive sleep apnea.

In 15 patients with ventricular asystole of 8.5 +/- 3.5 seconds (range 5.0 to 16.8) occurring exclusively during obstructive sleep apnea, electrophysiologic study of sinus node function and atrioventricular conduction before and after administration of intravenous atropine (0.02 mg/kg) was performed. Electrophysiologic parameters of sinus node function were normal in 12 of 15 patients (80%) and atrioventricular (AV) nodal function was normal in 7 patients (47%). Almost all abnormal findings of sinus node function and AV nodal function were reversible by administration of atropine. The HisPurkinje system function was normal in 6 patients (40%). Prolonged HV intervals (57 to 73 ms) were found in 9 patients (60%). Intra- or infra-His block was not observed in any patient. In summary, electrophysiologic parameters of sinus node function and AV conduction were normal or only slightly abnormal in all 15 study patients, which suggests that prolonged ventricular asystole during obstructive sleep apnea is not due to fixed or anatomic disease of the sinus node or the AV conduction system.

Atrioventricular Node↗
PubMed1996

[The effect of preischemic blood sugar concentration on hemodynamics and regional organ blood flow during and following cardiopulmonary resuscitation (CPR) in swine].

UNLABELLED: Blood glucose alterations prior to cerebral ischaemia are associated with poor neurologic outcome, possibly due to extensive lactic acidosis or energy failure. Cerebral effects of hyper- or hypoglycaemia during cardiopulmonary resuscitation (CPR) are less well known. In addition, little information is available concerning cardiac effects of blood glucose alterations. The aim of this study was to evaluate the effects of pre-cardiac-arrest hypo- or hyper-glycaemia compared to normoglycaemia upon haemodynamics, cerebral blood flow (CBF) and metabolism (CMRO2), and regional cardiac blood flow during CPR subsequent to 3 min of cardiac and respiratory arrest and after restoration of spontaneous circulation. METHODS: After approval by the State Animal Investigation Committee, 29 mechanically ventilated, anaesthetised pigs were instrumented for haemodynamic monitoring and blood flow determination by the radiolabeled microsphere technique. The animals were randomly assigned to one of three groups: in group 1 (n = 9) blood glucose was not manipulated; in group II (n = 10) blood glucose was increased by slow infusion of 40% glucose to 319 +/- 13 mg/dl; in group III (n = 10) blood glucose was lowered by careful titration with insulin to 34 +/- 2 mg/dl. After 3 min of untreated ventricular fibrillation and respiratory arrest, CPR (chest compressor/ventilator (Thumper) and epinephrine infusion) was commenced and continued for 8 min. Thereafter, defibrillation was attempted, and if successful, the animals were observed for another 240 min. Cerebral perfusion pressure (CPP), CBF, CMRO2, coronary perfusion pressure (CorPP), and regional cardiac blood flow were determined at control, after 3 min of CPR, and at 10.30, and 240 min post-CPR. RESULTS: In group 1. 4/9 animals (44%) could be successfully resuscitated; in group II 4/10 (40%); and in group III 0/10 (0%). Prior to cardiac arrest, mean arterial pressure, CPP, and CorPP in group III were significantly lower compared to groups I and II. In group I. CPP during CPR was 26 +/- 6 mmHg; CBF 31 +/- 9 ml/ min/100g CMRO2 3.8 +/- 1.2 ml/ min/100 g; CorPP 18 +/- 5 mmHg; and left ventricular (LV) flow 35 +/- 15 ml/min/100 g. In group II; CPP = 21 +/- 5; CBF 21 +/- 7; CMRO2 1.8 +/- 0.8; CorPP 16 +/- 6; and LV flow 22 +/- 9; and in group III: CPP 15 +/- 3; CBF 11 +/- 8; CMRO2 1.5 +/- 1.1; CorPP 4 +/- 2; and LV flow 19 +/- 10. During the 240-min post-resuscitation period, there were no differences in CBF, CMRO2, or LV flow between groups I and II. CONCLUSION: Hypoglycaemia prior to cardiac arrest appears to be predictive for a poor cardiac outcome, whereas hyperglycaemia does not impair resuscitability compared to normoglycaemia. In addition, hyperglycaemia did not affect LV flow, CBF, or CMRO2. However, it has to be kept in mind that haemodynamics and organ blood flow do not permit conclusions with respect to functional neurologic recovery or histopathologic damage to the brain, which is very likely to be associated with hyperglycaemia.

Anesthesia↗
PubMed1996

Influence of D-net (European GSM-Standard) cellular phones on pacemaker function in 50 patients with permanent pacemakers.

The widespread use of cellular phones in the last years has prompted some recent studies to suggest an interference of pacemaker function by cellular phone usage. To determine the risk of pacemaker patients using D-net cellular phones, we tested 50 patients with permanent pacemakers after routine pacemaker check by short phone calls using a cellular phone (Ericsson, D-net, frequency 890-915 MHz, digital information coding, equivalent to the European Groupe Systemes Mobiles standard). A six-channel surface ECG was continuously recorded from each patient to detect any interactions between pacemakers and cellular phones. Phone calls were repeated during the following pacemaker settings: (1) preexisting setting; (2) minimum ventricular rate of 90 beats/min and preexisting sensitivity; and (3) minimum ventricular rate of 90 beats/min and maximum sensitivity without T wave oversensing. Only 2 (4%) of 50 patients repeatedly showed intermittent pacemaker inhibition during calls with the cellular phone. Both pacemakers had unipolar sensing. Therefore, although interactions between cellular phone use and pacemaker function appear to be rare in our study, pacemaker dependent patients in particular should avoid the use of cellular phones.

Aged↗
PubMed1996

Heart rate variability and major arrhythmic events in patients with idiopathic dilated cardiomyopathy.

This prospective study of 71 patients with idiopathic dilated cardiomyopathy (IDC) and preserved sinus rhythm was designed to evaluate the relation between heart rate variability (HRV) and subsequent major arrhythmic events. Standard time- and frequency-domain HRV parameters were obtained from analysis of 24-hour Holter ECG recordings. During a mean follow-up of 15 +/- 5 months, major arrhythmic events including sustained ventricular tachycardia, ventricular fibrillation, and sudden cardiac death occurred in 10 of the 71 study patients (14%). Neither time- nor frequency-domain indices of HRV differed significantly between patients with and patients without subsequent major arrhythmic events. However, there was a trend toward a lower standard deviation of the average normal RR interval for all 5-minute segments of the 24-hour recording (68 +/- 17 ms vs 80 +/- 31 ms; P = 0.06) in patients with major arrhythmic events. In addition, the percentage of adjacent normal RR intervals differing > 50 ms over the recording period tended to be lower in patients with major arrhythmic events (6% +/- 3% vs 9% +/- 6%; P = 0.08). Our results indicate a tendency toward attenuated parasympathetic activity in IDC patients with subsequent major arrhythmic events compared to arrhythmia-free patients. Larger studies with longer follow-up periods are necessary to clarify the role of HRV measurements for arrhythmia risk prediction in patients with IDC.

Adolescent↗
PubMed1996

Clinical significance of increased OT dispersion in the 12-lead standard ECG for arrhythmia risk prediction in dilated cardiomyopathy.

QT dispersion was determined from the 12-lead standard ECGs from 107 patients with idiopathic dilated cardiomyopathy (IDG) and compared to QT dispersion measurements in 100 healthy age and sex matched controls. QT dispersion, rate corrected QT dispersion and adjusted QTc dispersion were significantly greater in patients with IDC compared to controls. During a prospective follow-up of 13 +/- 7 months, arrhythmic events, defined as sustained VT, VF, or sudden death, occurred in 12 (11%) of 107 study patients with IDC. QT dispersion was increased in patients with arrhythmic events compared to patients without arrhythmic events during follow-up (76 +/- 17 vs 60 +/- 26 ms; P = 0.03). Differences in QTc dispersion and adjusted QTc dispersion between patients with and without arrhythmic events, however, failed to reach statistical significance. Thus, although QT dispersion was increased in patients with IDC and arrhythmic events during follow-up, its clinical usefulness for risk stratification appears to be very limited due to the large overlap of QT dispersion among patients with and without arrhythmic events.

Arrhythmias, Cardiac↗
PubMed1996

Value of time- and frequency-domain analysis of signal-averaged electrocardiography for arrhythmia risk prediction in idiopathic dilated cardiomyopathy.

Signal-averaged electrocardiography (SAECG) was performed in 120 consecutive patients with idiopathic dilated cardiomyopathy (IDC), and in 60 healthy controls. Time-domain analysis of SAECGs revealed ventricular late potentials in 27 of 120 patients with IDC (23%) compared to 2 of 60 controls (3%; P < 0.05). Frequency-domain analysis of SAECGs showed ventricular late potentials in 9 of 120 patients with IDC (8%) compared to none of the 60 controls (0%, P < 0.05). During a prospective follow-up of 15 +/- 7 months, serious arrhythmic events, defined as sustained ventricular tachyarrhythmias or sudden death, occurred in 17 of 120 patients with IDC (14%). The sensitivity, specificity, and positive and negative predictive values of ventricular late potentials for serious arrhythmic events were 35%, 80%, 22%, and 88% for the time-domain analysis, and 18%, 94%, 33%, and 87% for the frequency-domain analysis of SAECG, respectively. Thus, neither the time-nor the frequency-domain analysis of SAECG appears to be useful for risk stratification in the setting of IDC in view of their low sensitivity and low positive predictive value for serious arrhythmic events during follow-up.

Action Potentials↗
PubMed1996

Alcohol and rhythm disturbance: the holiday heart syndrome.

The association between alcohol use and rhythm disturbances, particularly supraventricular tachyarrhythmias in apparently healthy people is called "holiday heart syndrome". The syndrome was first described in persons with heavy alcohol consumption, who typically presented at weekends or after holidays, but it may also occur in patients who usually drink little or no alcohol. The most common rhythm disorder is atrial fibrillation, which usually converts to normal sinus rhythm within 24 hours. The incidence of the holiday heart syndrome depends on the drinking habits of the studied population. The holiday heart syndrome should be considered particularly as a diagnosis in patients without overt heart disease presenting with new onset atrial fibrillation. Though recurrences occur, the clinical course is benign and specific antiarrhythmic therapy is usually not warranted.

Alcohol Drinking↗
PubMed1996

[Value of old and new electrocardiography criteria for differential diagnosis between ventricular tachycardia and supraventricular tachycardia with bundle branch block].

In 240 tachycardias with wide QRS-complex (> or = 120 ms), the value of the "old" ECG criteria published in 1978 by Wellens and coworkers was compared to the "new" ECG criteria published in 1991 by Brugada and coworkers for the differential diagnosis of tachycardias with wide QRS-complex. As main result of the study, it could be demonstrated that with the old as well as with the new ECG criteria a sensitivity of more than 90% for the correct diagnosis ventricular tachycardia can be reached. The specificity of the old and new ECG criteria for the diagnosis ventricular tachycardia is 70% and 72% for tachycardias with right bundle branch block configuration and 87% each for tachycardias with left bundle branch block configuration. The combined use of the old and the new ECG criteria in this study could not increase sensitivity and specificity for the diagnosis of ventricular tachycardia. Therefore, it does not appear to be important for the differential diagnosis of tachycardias with wide QRS-complex whether the old or the new step diagnostic criteria are being used, but that either the old or the new ECG criteria are being used correctly.

Adult↗
PubMed1995

[First experiences with temporary vena cava filters].

AIM: For prophylactic measures we used 3 different temporarily insertable vena cava filters. MATERIAL AND METHODS: In 49 patients we inserted 12 Cook-filters (6 transjugular, 6 transfemoral), 11 Angio-cor-filters (1 transjugular, 10 transbrachial), 26 Antheor-filters (1 transjugular, 1 transfemoral, 24 transbrachial). 35 patients underwent a lysis therapy, 11 a major operation of the pelvis, and 3 patients a Caesarean section. RESULTS: No patient suffered from a clinically significant pulmonary embolism after filter insertion, but complications occurred caused by the basic therapy (1 lethal abdominal aortic aneurysm operation, 1 cerebral bleeding, 2 retroperitoneal haematomas, 2 streptokinase fever reactions, 1 compartment syndrome, 1 macro-haematuria) or by therapy joined with the filters insertion (2 groin haematomas, 2 haematomas of the bend of the elbow, 2 subclavian vein thrombosis, 1 catheter dislocation, 1 infection, 1 air embolism, 1 break of a leg of the filter basket). CONCLUSION: Temporary vena cava filters are highly efficient in preventing pulmonary embolism, but the side-effects show that they should only be inserted in patients with known deep vein thrombosis and a high risk treatment of the underlying disease.

Evaluation Studies as Topic↗
PubMed1995

Shock occurrence and survival in 49 patients with idiopathic dilated cardiomyopathy and an implantable cardioverter-defibrillator.

To determine shock occurrence and survival, 49 patients with idiopathic dilated cardiomyopathy presenting with cardiac arrest (82%), syncope (12%) or ventricular tachycardia without syncope (6%) were followed for 28 +/- 28 months after cardioverter-defibrillator (ICD) implant according to the intention to treat principle. Using the Kaplan-Meier method, the actuarial incidence for any spontaneous shocks was 20%, 58%, and 77%, and the incidence of appropriate shocks was 16%, 49%, and 72% at 1, 3, and 5 years of follow-up, respectively. Only two of 49 study patients (4%) with an active ICD died suddenly during follow-up. Another two patients, however, with an inactive device died suddenly, resulting in a sudden death rate of 2% per year with an active ICD, and 5% per year, according to the intention to treat principle. The incidence of cardiac death from any cause was 8%, 25%, and 35%, and the incidence of total mortality was 14%, 39%, and 49% during 1, 3, and 5 years of follow-up, respectively. There was no difference in the Kaplan-Meier survival curves for shocked vs non-shocked patients. Thus, in this selected patient population with idiopathic dilated cardiomyopathy the majority of patients received 'appropriate' shocks during follow-up, and the sudden death rate with active ICD is low.

Cardiomyopathy, Dilated↗
PubMed1995

Invasive electrophysiological evaluation of patients with sleep apnoea-associated ventricular asystole-methods and preliminary results.

Twelve patients (aged 48 +/- 12 y) with ventricular asystole of >3 s due to complete atrioventricular (AV) block (n = 8), sinoatrial (SA) block or sinus node arrest (n = 3) or both (n = 1) associated with obstructive sleep apnoea underwent invasive electrophysiological evaluation of sinus node function and AV conduction properties before and after administration of atropine (0.02 mg kg-1). Ventricular asystole lasted for 5.9 +/- 2.8 s (range 3.1-13 s). Sinus node function was assessed by measurement of sinus node recovery time, sinoatrial conduction time, and the response of sinus rate to atropine. Parameters of AV-conduction assessment included AH- and HV-intervals, AV- and VA-Wenckebach periods, and effective refractory period of the AV node before and after atropine. Sinus node function was normal in 11 of the 12 study patients and moderately abnormal in 1 patient. AV-nodal function was normal in 8 patients and moderately abnormal in 4 patients. A slightly prolonged HV-interval (59-63 ms) was present in 6 patients. Intra- or infra His block was not observed in any patient. In conclusion, normal or only moderately abnormal electrophysiological findings in patients with sleep apnoea-associated ventricular asystole suggest that a neurally mediated cardioinhibitory reflex may cause ventricular asystole in these patients. This sleep apnoea-triggered 'vasovagal' reflex may unmask pre-existing mild to moderate structural abnormalities of the AV conduction system.

Journal Article↗
PubMed1995

Intermittent regional therapy with rt-PA is not superior to systemic thrombolysis in deep vein thrombosis (DVT)--a German multicenter trial.

In a prospective and randomized multicenter trial the efficacy of intermittent regional and systemic thrombolytic therapy for DVT was evaluated. 137 patients with phlebographically confirmed acute DVT above the calf region were treated with 20 mg of rt-PA for 4 h each day. Thrombolysis was applied either locally via a dorsal pedal vein of the firmly bandaged affected leg or systemically using a cubital vein. Treatment lasted for 4-7 days, and during this time unfractionated heparin was applied continuously with the dosage adjusted according to aPTT (1.5-2.0 times the normal value). A second phlebography was performed within 24 h after the end of treatment. Results were evaluated by an independent radiologist who was unaware of the treatment given. Significant thrombolytic results (e.g. lysis of more than 50% of the original thrombus and complete recanalization of all affected veins) were reached in only 1/3 of all patients. Rates of recanalization did not differ in both groups and bleeding complications occurred in 26.5%. We conclude that intermittent local or systemic application of 20 mg rt-PA seems to be ineffective in the treatment of DVT.

Adolescent↗
PubMed1994

[The differentiation between premature thelarche and pubertas praecox on the basis of clinical, hormonal and radiological findings].

In a retrospective study of 39 girls (aged 10 months to 7 10/12 years) with premature breast development criteria for distinguishing between premature thelarche and precocious puberty were analysed. Serum estradiol levels and bone age were determined and a test with luteinizing hormone-releasing hormone (LHRH) performed (inclusion criteria). On the basis of the LHRH test and bone age, premature thelarche was diagnosed in 29 patients and precocious puberty in ten: while those with premature thelarche had a follicle-stimulating hormone (FSH) pattern of rise, in those with precocious puberty the rise in gonadotropin was of the LH type. The LH/FSH ratio 30 min after stimulation was < 1 (median 0.15 [0.03-0.34] in patients with premature thelarche, but > 1 (median 2.1 [1.34-5.67] in those with precocious puberty. Bone age was accelerated by at least 18 months in those with precocious puberty, but it corresponded to their chronological age or was only slightly accelerated in those with premature thelarche. These data thus indicate that premature thelarche and central precocious puberty can be reliably distinguished by the LHRH test and bone age.

Age Determination by Skeleton↗