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Biomedical subjects

F Kaindl

Publications and source records attributed to F Kaindl.

At least 37 records · Page 2Linked to original sources

Diagnostic value of exercise testing versus long-term ECG in evaluation of arrhythmias in old age.

The usefulness of exercise testing (ET) in old age is so far undefined particularly for detection of arrhythmias. We compared the diagnostic value of ET with 24-h long-term ECG recording (LT-ECG) in patients older than 70 years that were evaluated because of symptoms possibly related to arrhythmias. In 37 patients (age 72.8 +/- 2.7 years) the incidence of ventricular arrhythmias (LOWN greater than or equal to 1) was greater during ET (67%) than during 24-h LT-ECG recording (48%, P less than 0.01). Complex ventricular arrhythmias were detected in 6/37 patients (16%) by ET, in 9/37 patients (24%) by LT-ECG, in one patient (3%) by both tests and in 14/37 patients (37%) by one of the two tests, while 23/37 patients (63%) had no significant complex arrhythmias recorded by either test. During ET 12 patients (32%) showed signs of myocardial ischaemia with ST-depression greater than or equal to 0.2 mV and/or increasing angina pectoris. In 42% of these patients complex ventricular arrhythmias LOWN greater than or equal to 3 occurred during ET. Thus both ET and LT-ECG are useful methods to uncover arrhythmias in symptomatic patients older than 70 years and have to be considered as complementary tools.

Aged↗

Radionuclide imaging after coronary vasodilation: myocardial scintigraphy with thallium-201 and radionuclide angiography after administration of dipyridamole.

Tl-201 imaging was performed in 194 patients who had undergone coronary angiography which had demonstrated coronary artery disease in 149 and normal coronary vessels in 45.91 patients had had previous myocardial infarction. Sensitivity for dipyridamole stress imaging was 92% for all 149 patients. 79% for the patients without previous infarction. Specificity was 81%. In a subgroup of 40 patients (32 patients with reversible Tl-201 defects and 8 normals), an additional dipyridamole wall motion study was performed in order to evaluate the correlation of Tl-201 perfusion abnormalities and ventricular function after dipyridamole. Only 19% of the patients had a dipyridamole-induced drop of global left ventricular ejection fraction, 31% showed dipyridamole-induced wall motion abnormalities; the predictability of specific vessel involvement by regional wall motion and regional ejection fraction assessment was 26% as compared with 70% for thallium imaging. Tl-201 perfusion defects after dipyridamole administration can also occur independent of ischaemia-induced changes in global and regional ventricular function. Coronary vasodilation with dipyridamole using Tl-201 imaging is a reliable alternative method in patients with coronary artery disease with an accuracy comparable to exercise studies with the advantage of not necessarily needing ischaemia as an endpoint of the test.

Cineangiography↗

Reversible end-of-life indicator leading to erroneous pacemaker replacement-pitfalls of telemetry.

In several modern pacemakers, end-of-life (EOL) is indicated by a single-step rate drop, which is initiated by a voltage-sensitive electronic switch. This switch may also be activated by other causes, such as very short voltage drops, low temperatures, and electrocautery. We report a case in which a Cordis 233 F Sequicor II pulse generator was operating at 51.6 bpm in VOO mode at the time of implantation. As telemetry seemed to indicate that back-up pacing (the EOL indicator in this model) was "off," it was erroneously assumed that the pacemaker was not working properly. The unit was replaced by another impulse generator. At laboratory testing, the pacemaker was within specifications, when back-up pacing was separately programmed off. In conclusion, physicians should be aware of the new phenomenon of reversible EOL indicators, and that they may not rely on telemetry in this respect. Future pacemakers should incorporate a telemetry message which prevents similar misunderstandings.

Equipment Design↗

Chronic hemodialysis: high risk patients for arrhythmias?

UNLABELLED: Patients with end-stage kidney disease undergoing chronic maintenance dialysis (HD) are a high risk group for sudden death due to cardiovascular complications. It was the aim of the study to investigate the quantity and quality of arrhythmias during HD and between two consecutive HD (interval, I) with regard to the reproducibility of the expected results. 15 patients (8 males, 7 females) underwent continuous Holter monitoring (LT-ECG) under ambulatory conditions over 96 h including two HD ( HD1 + HD2 ) and two intervals (I1 + I2). The LT-ECG recordings were analysed with the computer assisted ' Multipass -Scanning' system with regard to heart rate (HR), supraventricular premature beats (SPB), ventricular ectopics (PVC) and malignant ventricular arrhythmias. RESULTS: The HR demonstrated a typical, well-known circadian pattern with remarkable increase of the HR during each HD. Except for rare, single SPB and/or PVC, no supraventricular or ventricular arrhythmias could be detected reproducibly. Single PVC occurred in patients with a lower potassium value. No malignant ventricular arrhythmias were found. In comparison to previously published studies, which demonstrated a high incidence of malignant ventricular arrhythmias, these conflicting results were due to differences in patients' recruitment (underlying disease, age, etc.), the performance of HD (duration, ion concentration of the dialysate etc.), serum potassium levels and drug medication (digitalis, quinidine). In summary, chronic HD per se did not enhance the risk of malignant arrhythmias in patients with end-stage kidney disease.

Adolescent↗

[Diagnosis of syncopes in suspected arrhythmias].

Several mechanisms lead to attacks with unsuspected sudden and intermittent loss of consciousness. A major cause for such syncopes are arrhythmias. Only in rare cases it is possible to register an ECG during a typical attack despite many newer methods as long-term ECG (LT-ECG), exercise stress test and electrophysiologic investigations. LT-ECG does not record the ECG only during symptomatic periods (syncopes, dizziness, palpitations etc), but also registers asymptomatic AR, which can be precursors of SY. Carotid sinus massage is a valuable tool for the detection of a cardio-inhibitory Carotid-Sinus-Syndrome, which can be treated with PM-implantation. Exercise stress testing induces ventricular arrhythmias, which also indicates AR as underlying cause for SY. Using the invasive electrophysiologic investigation methods the importance measuring supraventricular parameters (SNRT, SA-, AH-interval) or parameters of the AV-nodal conduction (AH-, HV-interval) decreased in contrast to the ventricular stimulation techniques. With these invasive procedures ventricular tachycardias, ventricular flutter or fibrillation can be induced in selected patients, which indicates also a possible arrhythmogenic substrate for SY. In a suspected arrhythmogenic genesis of SY it has to be recommended to perform LT-ECG, carotid sinus massage, exercise stress testing and -- in selected patients -- electrophysiological investigations in addition to the routine-ECG to exclude or confirm arrhythmias as possible substrate for SY.

Arrhythmias, Cardiac↗

[Ergometry and long-term ECG for assessing bradycardiac and tachycardiac heart rhythm disorders in symptomatic patients over 70].

The usefulness of exercise testing and long term-ECG recording in old age was evaluated in a retrospective study. During a period of 24 months 317 long-term-ECGs in 195 patients greater than 70 years and 208 exercise tests in patients greater than 70 years were performed. The mean age of the patients was 73 +/- 3 years. Long-term ECG revealed a high incidence of supraventricular arrhythmias, while PVCs were found in only 28.7% of patients and PVCs greater than 30/h in only 7.3% of patients. Complex ventricular arrhythmias occurred in 25% of patients. Long-term ECG recording appeared to be of particular value in detecting abnormal regulation of heart rate and bradycardia, although symptom correlation with arrhythmias recorded was rare. Exercise testing revealed a higher incidence of PVCs with PVCs recorded in 67% of patients and PVCs greater than 2/min in 42% of patients. The incidence of complex ventricular arrhythmias was slightly greater compared to long-term recording with 29% of all patients. Exercise testing was particularly useful in detecting complex arrhythmias in patients with additional signs of myocardial ischemia (ST-segment depression and/or angina pectoris during increasing levels of exercise). Thus comparing both exercise testing and long-term ECG both appeared to be useful methods to uncover arrhythmias in symptomic patients older than 70 years and have to be considered as complementary tools. Exercise testing is particularly useful in recovering complex ventricular arrhythmias in patients with signs of myocardial ischemia during exercise. Long-term ECG on the other hand allows better recognition of bradycardias and conduction defects that may also be present and may contribute to the patients symptoms.

Aged↗

Chylopericardium: a rare cause of pericardial effusion.

A 21 year old man presented with asymptomatic, isolated chylopericardium. Despite echocardiography, radionuclide-angiography, computer tomography, and chemical analysis of the chylous effusion, the etiology remained obscure. After patent blue dye infusion into peripheral soft tissues, the appearance of coloring material in the effusion at 4 hours suggested direct communication of the pericardium with an apparently large thoracic duct. Fifteen months later, cardiomegaly persists in site of medium-chain triglyceride dietary restriction.

Adult↗

Reversible EOL-indicator: a new cause for low pacemaker rate.

A case is presented in which a new cause for decrease in pacemaker rate was encountered: six months after implantation of a Medtronic 5967 pacemaker, the first routine check-up revealed a rate of 62.5 ppm instead of 70 ppm. After application of a magnet, all measurements returned to normal. The cause for this phenomenon, which could not be attributed to battery depletion or oversensing, was probably a change of state of the flip-flop which is responsible for the sudden rate drop of 10% which serves as the end-of-life (EOL)-indicator in this pacemaker. This change of state may result from a very short decrease of power supply voltage during shipment or at the time of implant, and is fully and permanently reversible by performance of the magnet test. In order to prevent unnecessary pacemaker explants, future pacemaker circuits should be redesigned to eliminate the effect of very short voltage changes. Meanwhile, a routine magnet test should be performed immediately after implantation.

Electric Power Supplies↗

[Emission-computed tomography of the myocardium with the 7-pinhole collimator].

89 patients (78 with coronary artery disease, 11 normals) were studied comparatively with T1-201 planar myocardial scintigraphy and 7-pinhole emission tomography with a mobile gamma-camera. In 46 patients stress studies were performed, the other studies were performed as resting protocols. In 13 patients a correlation of scintigraphically determined infarct size calculated from the T1-201 tomograms with CK and CK-MB values (maximum values) in the acute infarction period was performed. 17 patients having undergone intracoronary streptolysis were studied to investigate the effect of this intervention. In patients without previous myocardial infarction (n = 35) sensitivity of 7-pinhole tomography was significantly superior over planar reading of images (83% for qualitative evaluation, 91% for quantitative analysis). In patients with previous myocardial infarction (n = 26) comparative sensitivities were not significantly different, although slightly higher, nevertheless the fraction of questionable findings was reduced from 9 to 4%, furthermore in 31% an additional information concerning size or localization could be obtained from the tomograms. Predictive diagnostic accuracy was highest for quantitative 7-pinhole tomography (91%) but not significantly different from qualitative tomography but higher than for planar imaging. Specificities of all methods were comparable. In patients during the acute phase of myocardial infarction a significant correlation (r = 0.76 for CK, r = 0.78 for CK-MB, p less than 0.01) was obtained with enzymatic markers of infarct size. In the group after intracoronary streptolysis 7-pinhole tomography was able to demonstrate a quantitative reduction of thallium infarct size in patients after successful lysis (23.5% vs 48.7%, p less than 0.01) although absolute quantitation is not possible with thallium-201 due to inherent biological limitations. Emission tomography using 7-pinhole collimation leads to an improvement of diagnostic accuracy in all patients with reversible ischemia and helps for better delineation of size and localization of infarct areas and could help in the assessment of interventional effects, as after intracoronary streptolysis.

Adult↗

Induction of ventricular tachycardia by pacemaker programming.

The induction of ventricular tachycardia or ventricular fibrillation by competitive pacing, especially in the setting of acute myocardial ischemia, is well known. A case of ventricular tachycardia induced by a multiprogrammable unipolar cathodal ventricular pacemaker is reported. The arrhythmia was caused by reprogramming, which necessitates a short switch to fixed rate pacing in this model (Spectrax 5985 SX). This potential hazard is not well established in patients with unipolar pacemakers. The use of the magnet as one of the preconditions for reprogramming should be avoided in future pacemakers.

Bradycardia↗

Myocardial perfusion evaluated by contrast echocardiography. A preliminary report.

The usefulness of contrast echocardiography for demonstration of myocardial perfusion was studied on six mongrel dogs. Two contrast agents tested were: (1) 0.9 percent saline solution, and (2) CO2-enriched saline solution (containing 0.2 ml CO2/10 ml). Only the latter solution produced an elucidation of the myocardium and allowed an estimation of the distribution and flow velocity of the contrast agent, which was characterized using the following three parameters: (1) transmural flow time (0.13 +/- 0.02 s x +/- SEM); (2) circumferential flow time (1.43 +/- 0.31 s); and (3) persistence time (42.0 +/- 4.3 s). There were no serious side effects on hemodynamics or heart rhythm. Thus, contrast echocardiography offers the possibility of detecting and quantitating myocardial perfusion.

Animals↗

[Hemodynamics of congestive cardiomyopathy].

202 patients with congestive cardiomyopathy have been classified according to their hemodynamic, angiographic, echocardiographic and scintigraphic findings: 72 patients were in the late stage (LS), 103 patients in an early stage (ES) and 17 patients showed a latent form of the disease. 48% of the hemodynamic ES were found to be clinically in stage IV NYHA and 53% of ES fell in class III. 40% of the patients with LS showed a stationary clinical course whereas 46% could improve their classification by one grade. The mortality in hemodynamic LS was 46% within an interval of 18 +/- 14 months after the diagnosis. In ES 64% showed a stable clinical course, where a 22% were deteriorating. Mortality in this group was 10%. Sensitivity and specificity of echocardiography (93 vs 80%) and radionuclide methods (80 vs 71%) were quite good in the late stage whereas in ES specificity was only 71% vs 80%. There was a discrepancy between the degree of myocardial impairment and clinical symptoms in the late stage whereas in the early stage there was no correlation between exercise capacity and LV-hemodynamics. Non-invasive methods allow the hemodynamic evaluation of the disease; invasive methods are required for clarification of diagnosis or establishing prognosis.

Adult↗

Plasma concentrations of plbatelet-specific proteins in coronary artery disease.

The plasma concentrations of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) were measured in 100 patients with documented coronary artery disease (CAD) and in 40 controls. 18 patients had had coronary artery bypass surgery (CABS), 25 patients were on therapy with beta-blocking agents and 19 were treated with oral anticoagulants. 38 patients with CAD received neither CABS nor beta-blocking or anticoagulating drugs. The highest plasma concentrations of beta-TG and PF4 were found in the patient group without medical or surgical treatment (patients versus controls: p less 0.01). Patients with CABS showed beta-TG and PF4 levels within the normal range. Patients with beta-blocking agents also had lower beta-TG and PF4 values than the patient group without therapy (p less than 0.05). By contrast, patients on oral anticoagulation therapy presented with similar plasma concentrations of beta-TG and PF4 as untreated patients. Our data indicate that surgical or medical treatment with beta-blocking agents, but not with oral anticoagulants, may have some influence on platelet function in patients with CAD. beta-TG and PF4 radioimmunoassay may be a simple method to study platelet involvement in various diseases and to evaluate possible influences of medical of surgical treatment on in vivo platelet function.

Adrenergic beta-Antagonists↗

Value of exercise testing for prediction of physical and psychosocial rehabilitation potential 3 months after acute myocardial infarction.

In 147 patients exercise tests were performed at the beginning and after 1 year of an ambulatory rehabilitation program. Measurements of both tests and the degree of functional improvement were correlated with patients' characteristics, the results of a psychological analysis using the Freiburger Personality Inventory and a patient's questionnaire for self-assessment. Among the major determinants for functional improvement were age, location of the infarct, rate of participation and greater initial functional impairment. High degree of psychosomatic impairment accompanied low levels of exercise capacity, the patients' self-assessment showed no correlation with exercise performance.

Adult↗