Biomedical subjects

Michał Lewandowski

Publications and source records attributed to Michał Lewandowski.

6 recordsLinked to original sources

PubMed2005

Implantable cardioverter-defibrillators in patients with hypertrophic cardiomyopathy -- dilemmas and difficulties.

INTRODUCTION: The implantation of a cardioverter-defibrillator (ICD) is an established method of sudden cardiac death (SCD) prevention. The value of ICD therapy in secondary prevention of SCD is unquestionable. Precise identification of high-risk patients and ICD use for primary prevention of SCD, especially in patients with hypertrophic cardiomyopathy (HCM), remain controversial. Problems include the high prevalence of complications associated with ICD implantation and optimal selection of ICDs. AIM: To estimate the frequency and type of complications after ICD implantations in HCM patients in a long-term follow-up. METHOD: The efficacy and safety of ICD therapy were estimated in 46 HCM patients with devices implanted for a secondary (n-18) or primary prevention (n-28) of SCD. RESULTS: During the mean follow-up period of 28.2+/-26.1 months (from 2 to 68) appropriate ICD interventions occurred in 10 (55%) patients of the secondary prevention group and in 3 (10%) patients of the primary prevention group. Complications were documented in 15 (33%) patients. The most frequent were inappropriate ICD interventions recorded in 14 (30%) patients. The causes of these inappropriate ICD shocks were: T-wave oversensing (7 patients), atrial fibrillation with rapid ventricular rhythm (3 patients), lead failure (2 patients), and sinus tachycardia (2 patients). In two patients infections of the ICD pocket requiring removal of the system occurred. Displacement of the lead occurred in one patient. There were no significant differences in the prevalence of complications between the primary and secondary prevention groups or in the number of inappropriate interventions with respect to ICD type. CONCLUSIONS: The high rate of appropriate ICD shocks provides proof of high ICD-based SCD prevention efficacy. There is a high rate of complications observed after ICD implantation with inappropriate interventions being the most frequent among them. This indicates that careful programming of the device as well as the use of a programme with T-wave oversensing prevention should be ensured.

Adult↗

PubMed2004

[Algorithm for diagnosing stable coronary artery disease].

UNLABELLED: The aim of the study was to develop simple algorithm for non-invasive estimating probability of the presence of CAD to optimize indications for cardiac catheterization. A prospective collection of clinical, electrocardiography (ECG), exercise electrocardiography (EE), dobutamine stress echocardiography (SE) and catheterization data was performed. All patients (n = 551, 65% male) complaining of chest pain, without prior history of myocardial infarction undergone EE (regarded as positive on the basis of > or = 1 mm ST-depression) SE (ischemia was defined as new or worsening wall motion abnormalities using a 16-segment model) and coronary angiography (CA): CAD was defined as > or = 50% narrowing of at least one major vessel. Two algorithms were developed with the use of probability analysis by computer program which employs Bayes' theory. They incorporated pretest variables: (age, gender, chest pain classification according to Diamond), ECG and results of one or two non-invasive test: EE and (or) SE. The studied population was divided into 3 groups on the basis of pretest likelihood of CAD: 1. low (< 10%), 2. intermediate (10-70%, in man divided into intermediate--low.: 10-29% and intermediate--high: 30-70%) and 3. high (> 70%). RESULTS: The prevalence of CAD in studied population was 61%. The sensitivity of the algorithm is 96% and specificity was 44%. Sensitivity and specificity of EE and SE was respectively: 93%, 21% and 85%, 69%). CONCLUSIONS: 1. An algorithm derived in our study is simple and may be useful in decision making that relates to CA. 2. We showed that when the likelihood of CAD is high on the basis of initial evaluation, diagnostic non-invasive testing is not indicated before CA, when the probability is intermediate or low, implementation of first choice test should be different in women (SE) and men (EE).

Aged↗

PubMed2004

Implantable cardioverter-defibrillators in children.

BACKGROUND: Implantable cardioverter-defibrillators (ICD) have been increasingly used in adult patients for the prevention of sudden cardiac death (SCD). The usefulness and feasibility of ICD implantation in children have been less well established. AIM: To analyse indications, results and safety of ICD therapy in children. METHODS: ICDs were implanted in seven children, aged from 6 to 17 years. All patients underwent cardiological evaluation which included analysis of medical history, physical examination, chest X-ray, standard ECG, 24-hour Holter ECG monitoring and echocardiography. RESULTS: In five children devices were implanted due to aborted sudden death (ventricular fibrillation) whereas in the remaining two - as a primary prevention of SCD. Three children had hypertrophic cardiomyopathy, one - dilated cardiomyopathy, one - mitral valve prolapse and QT prolongation, one - congenital long QT syndrome and the remaining patient - idiopathic ventricular tachycardia. Single-chamber devices were implanted in six children, and dual-chamber system - in one patient. In all patients endocardial leads were implanted and ICD pocket was formed under the greater pectoral muscle. During follow-up ranging between four months to 5.4 years, four children developed ventricular fibrillation or ventricular tachycardia which were terminated by appropriate ICD discharges. CONCLUSIONS: 1. ICD implantation in children is effective in the prevention of SCD. 2. In our population, the most frequent indications for device implantation were life-threatening ventricular arrhythmias occurring in patients with cardiomyopathy. 3. Cardiac arrest due to ventricular fibrillation may occur in children without a history of aborted SCD. 4. ICD implantation in children is feasible and safe.

Adolescent↗

PubMed2004

[Implication of probability analysis for diagnosis of stable coronary diseases. Comparison of non-invasive diagnostic tests].

UNLABELLED: A prospective collection of clinical (history), electrocardiography (ECG), exercise electrocardiography (EE), dobutamine stress echocardiography (SE) and catheterization data was performed in 551 patients with chest pain regarded as definite or probable stable angina pectoris. All patients (65% male) without prior history of myocardial infarction undergone clinical evaluation: chest pain classification according to Diamond, ECG, EE (regarded as positive on the basis of > or = 1 mm ST-depression), SE (ischemia was defined as new or worsening wall motion abnormalities using a 16-segment model) and coronary angiography (CA):CAD was defined as > or = 50% narrowing of at least one major vessel. Sensitivity and specificity of ECG, EE, SE was calculated: and results are as follows respectively: 23% and 87%, 93% and 21%, 85% and 69%. On the basis of these results with implication of probability analysis two algorithms were developed by computer program. They incorporated pretest variables: age, gender, chest pain classification, ECG and results of one or two non-invasive tests: EE and (or) SE. The sensitivity and specificity of the algorithm is 96% and 44%. CONCLUSIONS: 1. Chest pain characteristics remains an effective tool for estimating probability of CAD. 2. The diagnostic value of resting electrocardiography in stable CAD is low. 3. SE has comparably sensitivity but significantly higher specificity than EE. 4. We demonstrated that when the likelihood of CAD is high on the basis of initial evaluation, diagnostic non-invasive testing is not indicated before CA. 5. When the probability is intermediate or low, implementation of first choice test should be different in women (SE) and men (EE).

Adult↗

PubMed2003

[The diagnostic value of stress dobutamine echocardiography in stable coronary artery diseases].

UNLABELLED: The relation of stress dobutamine echocardiography test results to angiographic features was assessed in 551 patients with chest pain regarded as definite or probable stable angina pectoris. The indications for catheterization in each patient were determined at the discretion of the attending physician. All patients underwent diagnostic coronary angiography (clinically important coronary artery disease was defined as > 50 per cent narrowing of the diameter of at least one major vessel or > or = 50 per cent of the left main coronary artery) and stress dobutamine echocardiography (DSE): Ischemia was defined as new or worsening wall motion abnormalities using a 16-segment model. Sensitivity and specificity of DSE was calculated: 85% and 69% respectively for the entire group, 79% and 71% in women, 87% and 66% in men and compared with diagnostic value of the electrocardiographic exercise test (EE) in the same population. Sensitivity and specificity of the EE was respectively: 93% and 21% for the entire group, 91% and 16% in women, 94% and 27% in men. CONCLUSIONS: 1. DSE has comparable sensitivity but significantly higher specificity than EE. 2. Variables determining false positive result of DSE are as follows: mean maximal heart rate, reached % of the target heart rate and wall motion abnormalities present in single segment. 3. Variables determining false negative results are: sex (male) and one vessel disease. 4. Treatment with beta-adrenolytic agents increases incidence of nondiagnostic results of DSE.

Angina Pectoris↗

PubMed2002

Risk of thromboembolic complications in patients with permanent atrial fibrillation undergoing cardioverter-defibrillator implantation.

BACKGROUND: Cardioversion of atrial fibrillation (AF) carries the risk of thromboembolic complications and, therefore, anticoagulation therapy is routinely administered before and after this procedure. In patients with permanent AF who undergo implantation of cardioverter-defibrillator (ICD), anticoagulants are usually withdrawn during the perioperative period. However, in some patients sinus rhythm may be restored during defibrillation threshold (DFT) testing which potentially may increase the risk of thromboembolic complications. AIM: To assess the frequency of sinus rhythm restoration during ICD implantation in patients with permanent AF and the rate of both thromboembolic events and local bleeding complications which may occur due to temporary withdrawal of anticoagulation therapy and its re-initiation early after the procedure. METHODS: Permanent AF was present in 23 (12%) of 193 patients selected for ICD implantation. All patients received prolonged oral anticoagulation according to the generally accepted standards. Anticoagulation therapy was stopped few days before the procedure and replaced by low molecular weight heparin which was administered up to 24 hours before ICD implantation and re-initiated 12-24 hours afterwards. RESULTS: During DFT testing sinus rhythm was restored in 5 (21.7%) patients with AF. Clinical and DFT characteristics were similar in those who were converted to sinus rhythm and those who remained in AF. No thromboembolic events were noted in either group. Local haematoma at the site of ICD implantation occurred in two (8%) patients. CONCLUSIONS: Sinus rhythm was restored in 21.7% of patients with permanent AF who underwent ICD implantation. Temporary withdrawal of anticoagulation therapy did not increase the risk of thromboembolic complications, however, its early re-initiation after implantation resulted in an increase in local bleeding complication rate.

Journal Article↗