Radiofrequency catheter ablation of the bundle branch reentrant ventricular tachycardia.

Bundle branch reentrant ventricular tachycardia (BBRVT) has a suitable anatomic substrate for radiofrequency catheter ablation. However, the experience with this treatment is still small. In the current study, we examined the safety and the long-term efficacy of radiofrequency ablation in the cure of patients with BBRVT. Four patients with BBRVT, identified during electrophysiological study, underwent temperature-controlled radiofrequency ablation of the right bundle branch (RBB). All of them had syncope and structural heart disease with reduced left ventricular ejection fraction. The baseline examination revealed an intraventricular block, prolonged HV interval and inducible sustained VT because of bundle branch reentry in all patients. RBB was successfully abolished in all patients after the delivery of 3 +/- 1 radiofrequency pulses. After ablation, a permanent pacemaker was implanted in one patient with significantly prolonged HV interval. All patients were free of BBRVT during a mean follow-up of 20 months. One patient received implantable cardioverter-defibrillator for myocardial VT five months after ablation. Two patients developed congestive heart failure. Radiofrequency catheter ablation of the RBB is a safe and highly effective therapeutic procedure for definitive cure of BBRVT. Long-term prognosis of these patients depends mainly on the underlying heart disease and the treatment of other VT.

Dominant right ventricular infarction: is angioplasty the optimal therapeutic approach?

Approximately 30% of all acute inferior myocardial infarctions (AIMI) are accompanied by acute right ventricular infarction (ARVI) as a consequence of proximal right coronary artery (RCA) occlusion. Fifty per cent of all patients with ARVI manifest hypotension, jugular venous distension, and dyspnoea with clear lung fields, which is then considered as dominant acute RVI (ARVI). The in hospital mortality rate of patients with ARVI who are treated traditionally is very high. Thrombolytic therapy is relatively ineffective, while primary angioplasty is a more recent approach yet to be established as optimal treatment for patients with ARVI. Thirty-eight patients with dominant ARVI were admitted to our CCU over a period of 24 months. The patients were retrospectively divided into 3 groups according to treatment: Group I (n = 16): traditional treatment; Group II (n = 12): thrombolytic therapy (streptokinase); Group III (n = 10): angioplasty after urgent coronarography. We tested the difference in the number of deaths in all groups by the Fisher exact test. There was a significant difference in the number of deaths between Group I and Group III (P < 0.05). Mortality reduction was also noted between Group II and Group III, which, however, proved to be statistically insignificant.

The value of the QRS scoring system in assessing regional and global left ventricular ejection fraction early after myocardial infarction.

In 71 patients with a myocardial infarction (MI) (anterior in 27, inferior in 44 patients) global (GEF) and regional (REF) left ventricular ejection fractions were determined by radionuclide ventriculography and estimated from a 12 lead electrocardiogram (ECG), using Selvester's QRS score, during the early phase of a MI (15 to 21 days following MI). Global ejection fractions determined by radionuclide ventriculography and from ECG using Palmeri's method were: for all MI 40.8 +/- 12.6% vs 39.6 +/- 11.4%; in the group of anterior MI 32.0 +/- 10.0% vs 30.0 +/- 9.7% and in the group of inferior MI 48.9 +/- 12.0% vs 45.1 +/- 8.2%. A good correlation was found between global ejection fractions determined by radionuclide ventriculography and ECG, as well as between radionuclide GEF and ECG score. A weaker correlation was found between radionuclide GEF and enzymes among all MIs and in the group of anterior MI, while in the group of inferior MI this correlation was insignificant. The analysis of REF determined by radionuclide ventriculography and ECG showed the greatest abnormalities in the infarct region, but in the group of anterior MI, dysfunction was present in the whole left ventricle. The comparison of infarct-related REF derived from radionuclide ventriculography, with the QRS score showed a significantly higher correlation than the comparison with enzymes. ECG estimation of REF from a modified Palmeri's equation showed a better correlation with radionuclide REF than did GEF derived from the standard Palmeri's equation: anterior MI; r = 0.90 vs r = 0.82, inferior MI; r = 0.84 vs r = 0.69, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Global and regional parameters of left ventricular performance in healthy subjects during rest and exercise assessed by radionuclide ventriculography.

The aim of our study was to analyze numerous global and regional parameters of left ventricular (LV) performance during rest and exercise, in the group of 14 healthy subjects, by quantitative gated equilibrium ventriculography in left anterior oblique view (45 degrees). The global LV parameters at rest vs. exercise in our study were: heart rate 68.9 +/- 18.4 vs. 137.5 +/- 38.6; systolic blood pressure (mmHg) 121.8 +/- 18.2 vs. 178.6 +/- 31.2; diastolic blood pressure (mmHg) 82.1 +/- 10.8 vs. 90.7 +/- 12.4; double product 8,368.6 +/- 2,308.8 vs. 24,589.3 +/- 8,357.8; global ejection fraction (%) 61.9 +/- 15.4 vs. 72.8 +/- 12.8, end-diastolic volume index (ml/m2) 82.5 +/- 23.2 vs. 96.9 +/- 27.8; end-systolic volume index (ml/m2) 31.8 +/- 19.8 vs. 26.9 +/- 15.4; stroke volume index (ml/m2) 50.6 +/- 17.6 vs. 70.0 +/- 22.6; peak emptying rate (EDV/s) 3.4 +/- 2.6 vs. 8.3 +/- 3.8 and peak filling rate (EDV/s) 3.6 +/- 2.6 vs. 9.6 +/- 3.8. A significant difference (p < 0.05) between rest and exercise was found for all parameters. The highest values of LV regional ejection fraction were found in anterolateral and posterolateral region, while the lowest values were observed in inferoseptal and inferior regions. During exercise a significant increase of regional ejection fraction was found in all regions. The highest percent of radius shortening during rest was in anterolateral and posterolateral regions, and lowest in inferoseptal and inferior regions. The same sequence was found during exercise, and the difference in percent of radius shortening, between rest and exercise was significant in all regions. The observed normal values of global and regional parameters of LV function during rest may serve as a contribution for referent values. Our results on regional ejection fraction and the percent of radius shortening in rest, and their change during exercise, offer the possibility of additional information in the investigation of cardiac patients by means of radionuclide ventriculography.

Regression of ECG signs of myocardial infarction related to infarct size and left ventricular function.

Quantitative and qualitative analyses of Q waves and QRS scores were performed on 69 patients during the early phase of first myocardial infarction (MI) and 6 months subsequently. The regression of ECG signs of MI were compared with the enzymatically estimated size of MI, the location of MI, and with the changes of global ejection fraction (GEF) assessed by radionuclide ventriculography. Among 57 patients with Q wave MI a complete disappearance of ECG signs of MI was found in 9 (15.7%). Patients with MI of inferior location showed a significantly higher reduction of Q waves (p < 0.001) and QRS scores (p < 0.001) than the anterior MI group. In the group of 12 patients with non Q wave MI, 11 demonstrated complete regression of MI signs. Among all Q wave and non Q wave MIs, the authors found no significant difference in the size of MI between patients with and without complete regression of ECG signs of MI. The median of the percent of change of the QRS score was significantly higher (p = 0.04) in the group of patients with improved GEFs than in the group of patients with decreased or unchanged GEFs 6 months following acute MI. The sensitivity, specificity, and predictive values for improved left ventricular function according to the change of Q waves and ECG scores were 91%, 32%, and 62%; for changes of Q waves, 81%, 40%, and 63%; and for changes of ECG scores, 91%, 36%, and 64%, respectively. In the group of patients with non Q wave MI these values were 100%, 50%, and 91% as a result of ST-T disappearance.

[Clinical significance of the QRS-complex in the determination of myocardial infarct size]. / Klinicko znacenje QRS-kompleksa u odredivanju velicine infarkta miokarda.

In 60 patients myocardial infarction size was determined by electrocardiogram (ECG) using Selvester's QRS scoring system. These values were compared with the size of infarction as determined enzymatically using gram equivalent isoenzyme MB creatine kinase (gEq) and using maximum values of isoenzyme MB-CK. The results showed no statistically significant difference between the size of anterior and inferior infarction determined by gEq (25.19 +/- 13.59 vrs 22.48 +/- 14.04; p = 0.12 NS) and by maximum MB-CK (125.5 +/- 76.0 vrs 98.4 +/- 60.7; p = 0.12 NS). The size of myocardial infarctions determined by ECG was significantly larger anteriorly compared with the inferior infarcts (9.6 +/- 2.9 vrs 4.5 +/- 2.6; p = 0.001). In patients with anterior infarcts good correlations between the size of infarction determined by QRS scoring system and by gEq or maximum MB-CK were found (r = 0.69; p = 0.004 and r = 0.72; p = 0.001). In patients with inferior infarcts the correlations between QRS score and gEq or maximum MB-CK were poor (r = 0.37; p = 0.02 and r = 0.45; p = 0.15). The causes of weak correlations in the results of described methods in inferior infarcts are discussed. Thus QRS scoring system provides new noninvasive and simple possibilities in determining the size of anterior and in inferior infarctions of the left ventricle.

Daily administration of furosemide in dilated cardiomyopathy--yes or no?

Seventeen patients with dilated cardiomyopathy (mean ejection fraction 22%) in the NYHA state III or IV were investigated. All patients fulfilled the criteria of an indication for administration of furosemide, since left ventricular filling pressure (LVFP, measured as pulmonary capillary pressure) was 20 or more mm Hg in all. This study investigates the effects of an acute (40 mg i.v.) administration of furosemide (observation period 0 to 90 minutes after administration). Conventional M-mode, 2-dimensional and Doppler-echocardiography was performed in all patients. Patients were divided into 2 groups according to the degree of (relative) mitral regurgitation (MR): group 1 with moderate to severe (n = 10) and group 2 with mild or no MR (n = 7), 90 minutes after administration of furosemide LVFP decreased by 76%. In group 1 this occurred together with a 23% rise of cardiac index and a fall of systemic vascular resistance of 21%. In group 2 cardiac index decreased by 22% with a rise of systemic vascular resistance of 14%. The chronic oral administration of furosemide over 4 weeks ameliorated the NYHA state of all patients by one grade. We conclude from our results that patients with advanced dilated cardiomyopathy profit only from acute administration of furosemide if a significant (relative) MR is present also. A low dose chronic oral administration of the drug, however, leads in any case to clinical amelioration.

[Infarct of the right half of the heart]. / Infarkt desne polovice srca.

Isolated right ventricular infarction is not rare, as it is generally believed. As a rule, right ventricular infarction occurs in association with left ventricular infarction. Diagnosis of right ventricular infarction can not be made clinically alone. It should be confirmed on the basis of the following diagnostic procedures: the transient ST-segment elevation derived from the electrocardiogram, formation of QS-complex in V4 right, hemodynamic monitoring, echocardiography and radionuclide ventriculography. Of all the diagnostic criteria the best sensitivity and specificity is achieved by a rise in right ventricular filling pressure, respectively, the ratio of the right to left ventricular filling pressure should be equal or higher than 0.65. Increasing importance is being attached to the diagnosis of right ventricular infarction, since the treatment of patients with predominant right ventricular insufficiency and low cardiac output differs considerably from that of left ventricular insufficiency. Comparing our experience with previous reports, it may be concluded that adequate fluid administration with positive inotropic drugs, particularly adrenergic substances, if required, is essential in the medical treatment of right ventricular infarction. Vasodilator therapy may be administered, too. If frequent bradyarrhythmias do not respond to usual treatment, atrial pacing or atrioventricular sequential pacing should be initiated.

[The importance of the claudication test performed on a treadmill and its use in clinical practice]. / Vrijednost klaudikacijskog testa na pokretnom sagu i njegova primjena u klinickoj praksi.

A group of 55 patients with lower limb occlusive arterial disease was submitted to a treadmill walking exercise test in order to estimate the walking exercise length. The treadmill speed was fixed at 3 km/h and the carpet incline was 0% and 12% respectively. Doppler method for blood pressure estimation was applied in 10 patients to art. brachialis and art. dorsalis pedis bilaterally prior to and 2.5 and 10 minutes after the test. The ankle pressure index was calculated prior and post exercise. Results showed 51 +/- 9% difference between patients walking (3 km/h/0%) and patients climbing (3 km/h/12%). Ischaemic pain and blood pressure fall over art. dorsalis pedis during exercise correlated significantly 2 and 5 minutes after the test. Arteria dorsalis pedis pressure at rest and 2 and 5 minutes post exercise was statistically significant. Blood pressure indices prior and post exercise were related in the same manner. There was no difference in art. dorsalis pedis pressure and ankle pressure indices in our control group. The walking treadmill exercise test showed to be a simple reliable method for estimation of the functional degree of lower limb arterial insufficiency and for assessment of their surgical or drug therapy.