Biomedical subjects

Ilona Kowalik

Publications and source records attributed to Ilona Kowalik.

12 recordsLinked to original sources

PubMed2005

Relationship between duration of repolarisation and T wave amplitude in patients with positive or negative T wave alternans.

BACKGROUND: Experimental studies documented the relationship between T wave alternans (TWA) and duration of refractoriness. To date, association between TWA and QT interval on standard ECG has not been examined. Aim. To assess the relationship between TWA and QT interval. METHODS: The study group consisted of 70 patients (57 males, mean age 56+/-16 years) with implantable cardioverterdefibrillator (ICD). TWA was measured using a high-resolution ECG obtained from surface orthogonal bipolar XYZ leads and analysed using a Fast Fourier transform. All recordings were performed during ventricular pacing at 100 betas/min. Correlation between T wave amplitude (T max) and QT interval (measured from R wave to T max) was calculated. RESULTS: TWA was found in 18 patients. In this group of patients, there was a significant positive correlation between Tmax and QT (r = 0.766), whereas in patients with negative TWA no such correlation was detected. CONCLUSIONS: (1) Positive correlation between QT and T max probably depicts the relationship between T wave amplitude and duration of repolarisation, which is associated with TWA; (2) methods used for T wave localisation, based on the identification of Q wave (with possible QT-RR correction) overestimate TWA due to periodic changes (with TWA frequency) in location of T wave in the analysed window; and (3) these results provide new insights in the genesis of TWA.

Adult↗

PubMed2005

[Influence of cardiopulmonary bypass on risk of AF after coronary artery bypass grafting].

Atrial fibrillation is the most common tachyarrhythmia after coronary artery bypass grafting. The etiology of this arrhythmia and factors responsible for its genesis are unclear. The aim of this study was to compare the frequency of AF in patients undergoing coronary artery bypass grafting without the use of cardiopulmonary bypass (CPB) with those undergoing CABG using standard CPB. The study population consisted of 325 patients who underwent coronary artery bypass grafting between June 2000 and December 2001 (mean age 60.02, range 38-83 years, 242 males). Each patient had continuous ECG monitoring since the operation to the third postoperative day. AF occurred in 100 of 325 patients (30.76%). Patients were divided into two groups according to the presence (group A-100 patients) or absence (group B-100 patients) of post-CABG AF. Patients in both groups were compared. Intraoperative variables were used to compare the two groups. Patients with AF were significantly older (66.04 +/- 7.88 vs. 60.49 +/- 9.74 p = 0.0001). There was no statistically significant difference in the incidence of atrial fibrillation between the patients after coronary artery bypass grafting procedures, performed with or without cardiopulmonary bypass.

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

[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↗

PubMed2004

[Pharmacological versus invasive treatment in patients with atrial fibrillation].

Aim of this prospective study was to assess quality of life (QoL), left ventricular (LV) function and exercise performance in two groups of patients (pts) with atrial fibrillation (Af) treated with: radiofrequency catheter ablation (RFA) and antiarrhythmic drugs (AA). Between 1996 and 2000 - 74 patients, 28 women, with drug refractory Af were enrolled by clinical indications for two modes of therapy: RFA and AA. RFA group consisted of 38 pts, 63.7 +/- 11.5 years old: 28 pts with RF AV Node ablation and pacemaker implantation (PI) and 10 pts with AV Node modification or right atrial isthmus RF ablation due to Af conversion to atrial flutter (Aflu) during medical therapy. AA group consisted of 36 pts, aged 59.7 +/- 13.8 years. Patients from RFA group suffered significantly more serious diseases than pts from AA group. No significant (sign.) differences between two groups were found in age, gender, arrhythmia history and number of AA taken. Pts were analyzed before entry, after 3 and 12 months of follow-up (3 mo. FU, 12 mo. FU) with following indices: LV function (Echo: EF & FS), exercise performance (treadmill test), QoL questionnaires, number of hospital admissions connected to arrhythmia or procedures (RFA & PI), number of AA drugs taken in RFA group. RFA group: Two deaths occurred due to end stage respiratory insufficiency (COPD), one pt required reposition of pacemaker lead. AA group: 3 pts required RFA due to uncontrolled Af/Aflu (AV Node ablation with PI - 1 pt, right atrial isthmus ablation - 2 pts). Analysis of two patients groups: LV function: Sign. improvement (EF & FS) in both groups in 12 mo. FU; Exercise performance: no sign. changes in 3 and 12 mo. FU. QoL: Arrhythmia scale: 3 mo. FU sign. reduction in both groups; 12 mo. FU reduction in RFA group only; Anxiety scale: 3 and 12 mo. FU sign. reduction of anxiety level in RFA group; Exercise and activity scales: 3 and 12 mo. FU sign. improvement in RFA group. During 3 and 12 mo. FU sign. less pts from RFA group required hospital admission versus pts from AA group. Sign. reduction in AA was noted in RFA group. Patients with symptomatic Af treated with RFA benefit from this kind of therapy more than patients treated with AA. Quality of life improvement visible in short term observation in patients from RFA group is still present after one year observation. Improvement in LV function is observed after one year in both groups of pts with Af.

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↗

PubMed2003

[Anti-ischemic effect of angiotensin-converting enzyme inhibitor, but not vitamin C, in patients with coronary artery disease treated with beta-blockers and nitrates. Randomized, cross-over, double-blind comparison].

Anti-ischemic effect of angiotensin-converting enzyme inhibitor--chinapril was examined by exercise tolerance test [ETT] in randomised, cross-over double blind comparison in 20 pts with coronary artery disease treated with beta-blockers and nitrates. After 8 weeks of chinapril treatment maximal work capacity and exercise duration were significantly greater in comparison with baseline values, respectively: 7,8 vs 6,7 METs (p < 0,05) and 416 vs 335 s (p < 0,05). Time to ST segment depression was significantly longer after chinapril treatment: 394 vs 298 s (placebo) p = 0,01) vs 277 s (baseline), p = 0,008. The number of patients with exercise ST depression was significantly lower (63% vs 100%). Rate pressure product wasn't changed after chinapril treatment. Vitamin C therapy did not have influence on ischemia signs in exercise tolerance test.

Adrenergic beta-Antagonists↗

PubMed2002

[Prognostic value of exercise tests performed 3 months after coronary artery grafting in evaluation cardiac events. 6 years follow-up].

Prognostic value of exercise test in evaluation of cardiac events were examined in 326 pts after coronary artery bypass grafting (CABG). During 6 years follow up 18 (5.5%) cardiac deaths and 23 (7.1%) myocardial infarctions were observed. Chest pains persisted in 116 pts (35.6%) and 37 (11.3%) pts needed hospital treatment. Coronary and bypass angiography were performed in 25 pts (7.7%) followed by PTCA in 8 pts (2.5%) and CABG in 5 (1.5%) pts. Exercise duration and maximal work capacity in exercise tests were significantly lower in pts with cardiac events. Reasons of exercise termination: ST segment depression, heart rate and blood pressure values were not different in pts with and without cardiac events and didn't have prognostic value. Patients with cardiac events had significantly reduced left ventricle function. The value of ejection fraction influenced significantly relative risk of cardiac death (p < 0.05).

Adult↗

PubMed2002

[Development of nitrate tolerance in individual patients with stable angina pectoris in various phases of therapy with oral isosorbide dinitrate].

The aim of the work was an individual assessment of the effect on coronary reserve exerted by the widely used drug from the group of nitrates--isosorbide dinitrate (ISDN) in conventional and slow-release (SR) presentations, in various doses. The patients--38 males with stable coronary disease were given orally, by randomised double blind method, conventional isosorbide dinitrate (ISDN) in 10 and 20 mg doses, and slow-release isosorbide dinitrate in 20 mg SR, 40 mg SR, 80 mg SR and 120 mg SR doses, or placebo for the first time and for 7 days: four times daily, three times daily (with a 12-hour break), twice daily (with an 18-hour break) and once daily. In each of the therapeutic methods, walking times were analysed during exercise test six hours following drug administration, that is total time (TT), time to angina (TA) and time to ischaemia (TI). A prolongation by > or = 20% of walking times after ISDN administration as compared to placebo in > 50% of patients was accepted as significant improvement. Six hours after the first administration, a significant improvement of TT, TA and TI as compared to placebo was observed in the case of ISDN 20 mg, 40 mg SR, 80 mg SR and 120 mg SR. After administration of the drugs four times daily no significant improvement was observed after any dose. After administration of the drugs thrice daily, significant improvement was found in the case of TA (80 mg SR) and TI (20 mg SR, 40 mg SR and 120 mg SR), after twice daily administration--in the case of TI (40 mg SR and 80 mg SR) and after once daily administration--in the case of TT (80 mg SR), TA (120 mg SR) and TI (40 mg SR, 80 mg SR and 120 mg SR). In > 50% of patients, the coronary activity of ISDN in higher doses persists for six hours in the case of the first time administration; continuous therapy leads to tolerance development and intermittent therapy makes possible to avoid it. Tolerance does not depend on patients' sensitivity to nitrates.

Administration, Oral↗

PubMed2002

[Comparative evaluation of the clinical effectiveness and the adverse effects of three different forms of nitrates in high oral doses in patients with stable angina pectoris].

UNLABELLED: The aim of this study was the comparative evaluation of antianginal efficacy and the adverse effects of 3 nitrates in oral doses: isosorbide dinitrate 80 mg in slow release form (ISDN-80), nitroglycerin 15 mg--slow release (NITRO-15) and pentaerythritol tetranitrate 100 mg in normal tablets (PENTA-100) in patients (pts) with stable angina pectoris. In a randomized, double-blind, cross-over and placebo (P) controlled study 15 men, with mean age 54.8 +/- 8.0 years, with stable angina, received single doses of: ISDN-80, NITRO-15, PENTA-100 or P. Clinical efficacy of the drugs was evaluated by analysis of the walking times: total (TT), to angina (TA), and to ischemia (TI) on treadmill during stress tests performed 2 and 6 hours (h) after drug ingestion; the adverse effects were registered during 6 h follow up. RESULTS: 2 h after ingestion all 3 study drugs improved significantly: TT, TA and TI in comparison to P. After 6 h the same parameters were improved by: ISDN-80 and NITRO-15, but PENTA-100 improved only TT and TA. After 6 h ISDN-80 significantly improved in comparison to NITRO-15: TT by 19.7% (p < 0.01), TA by 21.2% (p < 0.01) ant TI by 25.0% (p < 0.05), and in comparison to PENTA-100: TT by 32.1% (p < 0.001), TA by 33.4% (p < 0.001) and TI by 41.1% (p < 0.01). After 6 h NITRO-15 significantly improved TI in comparison to PENTA-100 by 13.1% (p < 0.05). The headaches, the most frequent adverse effects, occurred after ingestion of ISDN-80 in 6 pts, NITRO-15 in 4 pts, PENTA-100 in 3 pts and P in 1 pt. Among three evaluated nitrates ISDN-80 significantly improved the effort tolerance and the coronary reserve in the strongest way, NITRO-15 was intermediate in the clinical efficacy, but PENTA-100, the drug with the weakest antianginal efficacy, was the reason of the least number of the adverse effects.

Angina Pectoris↗

PubMed2002

[Safety of stress echocardiography with dobutamine used in patients with aortic stenosis and left ventricular dysfunction].

THE AIMS: The aim of the study was to assess the safety of dobutamine echocardiography (DE) in patients with aortic stenosis and left ventricular ejection fraction < or = 45%. METHODS: 162 patients (mean age 59 +/- 13, 64% males) with resting transvalvular peak gradient < 70 mmHg underwent standard DE (doses 5-40 micrograms/kg/min) in a multicenter study involving 10 centers from Poland and Hungary. This analysis involves a subset of 39 pts (34 M, 5 F, age 59 +/- 13) identified according to the criterion of EF < or = 45% and mean aortic gradient < or = 35 mmHg. Clinically indicated coronary arteriography was performed in all patients with left ventricular dysfunction. RESULTS: Peak dobutamine dose was 29 +/- 10 micrograms/kg/min. Peak heart rate was 112 +/- 26 bpm. Systolic arterial pressure was 148 +/- 20 mmHg and diastolic pressure 86 +/- 14 mmHg. Transaortic mean gradient and aortic valve area increased 35 +/- 34% and 19 +/- 15% during peak dobutamine dose, respectively. Ejection fraction improved 16 +/- 14%. The test was positive in 17 (43.6%) patients, negative in 11 (28.2%) patients and non diagnostic in 11 (28.2%) patients. There were no deaths, myocardial infarctions or episodes of sustained ventricular tachycardia as a result of DE. The test was terminated when the following conditions were met: Target heart rate (23.%). Left ventricular asynergy (46.2%). Maximal established dose achieved (7.7%). Side effects (20.5%). The most common side effects were ventricular arrhythmias (35.9%), dyspnea (20.5%) and hypotension < 20 mmHg (10.3%). CONCLUSION: Despite frequent side effects, DE can be safely performed in patients with aortic stenosis and depressed left ventricular contractility.

Adult↗

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↗