Effects of amiodarone on the P-wave triggered signal-averaged electrocardiogram in patients with paroxysmal atrial fibrillation and coronary artery disease.

The effects of a 6-week treatment with amiodarone on the P-wave triggered signal-averaged electrocardiogram in patients with paroxysmal atrial fibrillation and coronary artery disease have been studied. Amiodarone favorably influences P-wave triggered signal-averaged electrocardiographic parameters, predominantly in patients in whom amiodarone is effective in preventing paroxysmal atrial fibrillation.

Ventilatory response to exercise correlates with impaired heart rate variability in patients with chronic congestive heart failure.

In chronic congestive heart failure (CHF) an overactivity of muscle ergoreceptors and peripheral chemoreceptors may lead to an increased ventilatory response to exercise and contribute to the autonomic imbalance. The analysis of heart rate variability (HRV), which is a reliable method of studying autonomic regulations within the cardiovascular system, showed depressed HRV indexes in CHF, but predictors of abnormal HRV pattern in CHF remain controversial. Considering a common mechanism involved in generation of both abnormal ventilation and autonomic dysfunction in CHF, we hypothesized that impaired ventilation may be better than other variables of CHF severity in determining HRV parameters. Seventy-two patients with CHF (57+/-9 years, ejection fraction: 28+/-11%) underwent cardiopulmonary exercise testing; the relation between ventilation and carbon dioxide production (VE/VCO2) was used as an index of the ventilatory response to exercise. Time and frequency-domain measurements of HRV were derived from 24-hour electrocardiographic monitoring. Patients had reduced exercise tolerance with abnormal ventilatory response (peak oxygen consumption [VO2max]: 17.8+/-5.5 ml/kg/min, VE/VCO2: 36.0+/-9.8). Correlations were found between HRV measures and etiology, New York Heart Association (NYHA) functional class, and VO2max, but the strongest relation was observed for VE/VCO2 slope (r values from -0.33 to -0.65, p <0.01). In the multiple regression analysis only VE/VCO2 was found to correlate independently with all HRV measurements. To investigate the role of peripheral chemoreceptor overactivity as the mechanism of autonomic imbalance and the increased ventilatory response to exercise, we assessed peripheral chemosensitivity in 22 patients (mean value of peripheral chemosensitivity: 0.62+/-0.34 L/min/%SaO2, significantly higher than in normal controls, mean value: 0.29+/-0.20 L/min/%SaO2 in our laboratory). The activity of the peripheral chemoreflex inversely correlated with all parameters of HRV. Increased ventilatory response to exercise correlated with depressed HRV measures in patients with CHF better than other clinical variables. An important role of the increased peripheral chemosensitivity in this relation may be relevant, being also a potential link between functional severity and sympathovagal imbalance in CHF.

[Significance of atrial signal-averaged electrocardiogram analysis in diagnosis of paroxysmal atrial fibrillation in patients with mitral valve prolapse syndrome]. / Znaczenie analizy usrednionego sygnalu przedsionkowego w diagnostyce napadowego migotania przedsionków u chorych z wypadaniem platka zastawki dwudzielnej.

The aim of this study was to assess the clinical usage of recording time-domain parameters of atrial signal-averaged electrocardiogram (ASAECG) in diagnosis of paroxysmal atrial fibrillation (PAF) of patients with mitral valve prolapse (MVP). 85 patients with MVP recognized by echocardiography were divided into two groups: group I (MVP-PAG/+/) 41 pts (15 male and 26 female) mean age 37.1 +/- 8.9 with previously electrocardiographically documented episode of PAF, group II (MVP-PAF/-/) 44 pts (20 male, 24 female) mean age 39.1 +/- 14.3 without PAF. The control group III consisted of 35 persons: 24 male and 11 female in mean age 37.7 +/- 6.2 without any cardiovascular diseases. All patients underwent additional investigations included: T3, T4, electrocardiography, exercise-test with moving "running track", 24-hours monitoring ECG with Holter's method and ASAECG recording. The following time-domain parameters of ASAECG were calculated: the root mean square voltage of the terminal 10, 20, 30 ms of the filtered P-wave (RMS 10, 20, 30) and total time duration of filtered P-wave (PWD). The adaptation of time-domain parameters of atrial signal-average in differential diagnostics of PAF during MVP has appeared as useless from clinical point of view.

[Clinical significance of atrial signal-averaged electrocardiogram in patients with electrically-induced paroxysmal atrial fibrillation]. / Znaczenie kliniczne rejestracji usrednionego sygnalu przedsionkowego u chorych z wystymulowanym migotaniem przedsionków.

UNLABELLED: The aim of this study was to assess the diagnostic possibilities of recording of time-domain parameters of atrial signal-averaged electrocardiogram (ASAECG) in patients with electrically-induced paroxysmal atrial fibrillation (PAF). The investigation was done in 53 patients (34 male and 19 female) mean age 47.6 +/- 13.1 with electrically induced sustained PAF- > 30 sec (group I). As a controls were forty patients (28 male and 12 female) mean age 46.2 +/- 15.3 (group II). The following time-domain parameters of ASAECG were calculated: the root mean square voltage of the terminal 10,20,30 ms of the filtered P-wave (RMS10,20,30) and total duration of filtered P-wave (PWD) and also time duration of P-wave from Frank's leads X,Y,Z (XP,YP,ZP). The values of RMS10,20,30 were statistically significant lower in patients with PAF than in controls, respectively RMS10: 3.9 +/- 1.4 microV vs 5.4 +/- 2.3 microV, p < 0.005, RMS20: 5.3 +/- 2 microV vs 6.8 +/- 2.2 microV, p < 0.001 and RMS30: 6.8 +/- 2.1 microV vs 7.4 +/- 3.6 microV, p < 0.05. Also the values of PWD were significantly longer in group I: 121 +/- 14.6 ms than in group II: 113.9 +/- 13.5 ms, 1 p < 0.02. Analysing the values of XP,YP,ZP it's occurred that only YP in PAF patients was statistically longer than in control, respectively 111 +/- 14.8 ms vs 96.7 +/- 13.8 ms, p < 0.001. The best differential criteria for identification of patients with electrically-induced PAF were RMS20 < 6 microV and PWD > 118 ms and gave sensitivity of 52%, specificity of 79%, positive predictive value of 68%, negative of 66% and diagnostic accuracy of 67%. CONCLUSIONS: 1. In patients with electrically-induced PAF the lower values of RMS10,20,30 and longer PWD were detected. 2. The criteria for identification of patients with electrically-induced paroxysmal atrial fibrillation were the values of RMS20 < 6 microV and PWD > 118 ms.

[Correlations between left atrial size and parameters of averaged atrial signal in patients with paroxysmal atrial fibrillation in the course of ischemic heart diseases]. / Korelacje miedzy wielkoscia lewego przedsionka a parametrami usrednionego sygnalu przedsionkowego u chorych z napadowym migotaniem przedsionków w przebiegu choroby niedokrwiennej serca.

The aim of this study was to assess the correlation between left atrial size and atrial signal-averaged electrocardiogram (ALP) in time-domain and frequency analysis in patients with paroxysmal atrial fibrillation (PAF) during ischaemic heart disease (IHD). The study population consisted of 75 patients with PAF during IHD who were divided into two groups; gr. I (left atrial dimension 40 mm) and gr. II (left atrial dimension 40 mm). The control group (gr. III) consisted of 50 healthy subjects. Recording of ALP was carried out by HIPEC-200HA. The high gain ECG was recorded during basic rhythm with orthogonal Frank leads X,Y,Z. These signals were amplified, averaged and filters. The filtered signals were combined into a vector magnitude and time-domain and frequency analysis was done. These findings suggest that the size of the left atrium does not change time-domain and frequency parameters of ALP in patients with PAF and IHD. We noticed significant influence of IHD on these parameters. On the other hand frequency analysis of ALP did not show any uselessness in diagnostic identification of patients with PAF during IHD and healthy subjects.

[The effect of intravenously given amiodarone on maintenance of ventricular signal averaged electrocardiogram in patients with ischemic heart disease]. / Wplyw dozylnie podanego amiodaronu na zachowanie sie usrednionego sygnalu komorowego u chorych na chorobe niedokrwienna serca.

Recording of ventricular signal-averaged ECG (VSAE) were carried out in 19 patients suffering from ischemic heart disease before and after intravenously administration of amiodarone using a commercially available machine HIPEC-200 HA device of Aerotel's. The high gain ECG was recorded during basic rhythm with orthogonal Frank leads X, Y, Z. These combined into a vector magnitude and the QRS duration (QRS), the duration of low amplitude signals < 40 microV (LPD) and the root mean square voltage of the signals in the last 40 and 50 ms of the filtered QRS (RMS 40,50) were calculated for VSAE. It was time-domain analysis of VSAE. In frequency domain analysis were calculated the following parameters in range from 40 Hz to 400 Hz in linear scale: area ratio 20-50 Hz/0-20 Hz, peak and magnitude ratio and in logarithmic scale: energy spectrum > -60 dB and decibel drop at 40 Hz. Subsequently amiodarone hydrochloride was given intravenously 5 mg/kg c.c. and again time-domain and frequency domain analysis were done. Data presented are mean +/- standard deviation. Statistical comparisons were performed with paired t-Student test. Significance refers to a p values < 0.05. Time-domain analysis of VSAE didn't show any significant differences after amiodarone injection. During frequency-domain analysis of VSAE statistically significant differences were displayed in Frank lead X and Y for energy spectrum > -60 dB. In Frank lead X decrease of this parameter after amiodarone (from 3322 +/- 1057 dB-Hz to 2628 +/- 733) and in lead Y increase (from 2793 +/- 500 dB-Hz to 3199 +/-938 dB-Hz) was noticed. Our observation have indicated that intravenously application of amiodarone hydrochloride didn't change parameters in time-domain analysis. Statistically significant differences were noticed only during frequency analysis VSAE in logarithmic scale -energy spectrum > -60 dB but only in two leads X and Y.

[Effect of propafenone hydrochloride on atrial signal-averaged ECG in patients with paroxysmal atrial fibrillation]. / Wplyw chlorowodorku propafenonu na usredniony sygnal przedsionkowy u chorych z napadowym mitgotaniem przedsionków.

Oral propafenone hydrochloride effect was studied on atrial signal-averaged ECG (ASAECG) during time- and frequency-domain analysis in patients with paroxysmal atrial fibrillation (PAF) during ischemic heart disease (IHD). The study comprised 26 patients (15 female and 11 male) mean age 60.8 +/- 6.2. The dose of oral propafenone was 450 mg/day for all days. Recording of ASAECG and 24-hours Holter monitoring were made at baseline, after 10 days and after 6 weeks of propafenone therapy. Time-domain parameters were calculated for ASAECG: the root mean square voltage of the signals in the last 10, 20, 30 ms of the filtered P-wave (RMS 10, 20, 30) and total time duration of filtered P-wave (PWD) and time duration of P-wave for Frank leads X, Y, Z (XP, YP, ZP). During frequency-domain analysis of the terminal part of P-wave the following parameters were calculated in range from 40 Hz to 400 Hz: energy spectrum > -60 dB (A) and decibel drop at 4 Hz (Dd) in logarithmic scale and area ratio 20-50/0-20 Hz (Ar), magnitude ratio (MR1-7) in linear scale for a vector magnitude. Supraventricular arrhythmias were estimated quantitatively and qualitatively by Holter monitoring. The following parameters were estimated in a case of PAF recording: time of manifestation, duration, number of PAF episodes per day, mean heart rate during PAF and subjective symptoms. Moreover, comparable analysis of the following parameters: dimension of left atrial, age, sex, time duration of IHD and PAF and wall motion disturbances--hypokinesis and also left ventricular ejection fraction, mitral regurgitation was done between patients with effective and no effective of antiarrhythmic therapy. Our observation have indicated that oral propafenone therapy does not influence any statistically significant differences all time- and frequency-domain parameters of ASAECG in patients with PAF during IHD. Moreover, comparable analysis of above mentioned parameters has not showed statistically significant differences between examined patients with effective and lack of effective propafenone therapy.

[Effect of pharmacologic blockade of the autonomic system on time domain parameters of atrial and ventricular signal-averaged ECG in subjects with mitral valve prolapse]. / Wplyw farmakologicznej blokady ukladu autonomicznego na parametry czasowe usrednionego sygnalu przedsionkowego i komorowego u osób z wypadaniem platka zastawki mitralnej.

The aim of this study was evaluation of pharmacologic autonomic blockade on time-domain parameters of atrial (ASAECG) and ventricular signal-averaged ECG (SAECG) in patients with mitral valve prolapse syndrome (MVP) regarded 20 subjects with MVP (mean age 34.9 +/- 5.3) (group I) were studied as well as a control group consisting of 20 healthy subjects (mean age 37.5 +/- 4.6) (group II). Initially, two dimensional echocardiography with color doppler examination, ambulatory Holter monitoring, multistage treadmill exercise test, transoesophageal pacing (TEP), recording of ASAECG and SAECG were made. Subsequently, pharmacologic autonomic system blockade was done by using intravenously propranolol (0.1 mg/kg) and atropine (0.02 mg/kg). The following time-domain parameters of ASAECG were calculated: the root mean square voltage for the last 10, 20, 30 ms of filtered P-wave (RMS 10, 20, 30) and time duration of filtered P-wave (PWD). Moreover, the following parameters of SAECG were analyzed: the root mean square voltage of the signals in the last 40 and 50 ms of the filtered QRS (RMS 40, 50), the total time duration of QRS(t-QRS) and the duration of low amplitude signals < 40 microV (LPD). The autonomic blockade did not change significantly the obtained values of RMS 10, 20, 30 in subjects with MVP as follows: RMS 10 from 5.5 +/- 2.9 microV to 6.3 +/- 2.4 microV, RMS 20 from 8 +/- 3.7 microV to 8.5 +/- 2.4 microV and RMS30 from 10.2 +/- 4.9 microV to 10.3 +/- 3.3 microV. On the other hand, also the values of RMS 10 did not change statistically significant after blockade in control group (from 5.8 +/- 2.2 microV to 5.6 +/- 1.7 microV, p > 0.05), but the values of RMS20 i RMS30 increased significantly in this group, respectively from 7 +/- 3.1 microV to 8.3 +/- 3 microV (p < 0.02) and from 8.4 +/- 3.1 microV to 10.1 +/- 3.6 microV, (p < 0.05). The values of PWD have changed differently in the examined groups being under the influence of the autonomic blockade: in group I decreased from 119 +/- 12 ms to 114 +/- 28 ms (p > 0.05), whereas in group II increased from 110 +/- 13 ms to 116 +/- 9 ms (p < 0.02).(ABSTRACT TRUNCATED AT 400 WORDS)

[Effect of salbutamol on heart rate in patients with atrial fibrillation]. / Wplyw salbutamolu na czestosc serca u chorych z migotaniem przedsionków.

The influence of salbutamol aerosol on heart rate in patients with chronic atrial fibrillation was examined. The study comprised 15 patients (9 women and 6 man) in age 47-79 (mean 60) treated because of chronic obstructive pulmonary disease (COPD) with concomitant atrial fibrillation. The influence of salbutamol on heart rate was investigated during six hours ecg Holter monitoring (3 hours before and 3 hours after using salbutamol). The analysis showed that salbutamol aerosol in two doses increased heart rate calculated as mean heart rate per hour from 3-hours intervals from 4061 congruent to 1022.5 to 4185 congruent to 976 (p greater than 0.05). Mean value of blood pressure in one hour intervals did not change significantly. In patients with concomitant chronic atrial fibrillation and COPD salbutamol increased heart rate but difference between mean values before and after administration was not significant.

[Effect of pharmacologic blockade of the autonomic nervous system on electrophysiologic properties of the accessory pathway and atrioventricular node in patients with Wolff-Parkinson-White syndrome]. / Wplyw blokady farmakologicznej wegetatywnego ukladu nerwowego na wlasciwosci elektrofizjologiczne drogi dodatkowej i wezla przedsionkowo-komorowego u chorych z zespolem Wolffa-Parkinsona-White'a.

In 17 patients aged 21-61 (mean 32) with WPW syndrome the transoseophageal stimulation was performed before and after intravenous administration of propranolol (0.1 mg/kg b.w.) and atropine (0.02 mg/kg b.w.). Pharmacological blockade of the autonomic nervous system resulted in statistically significant increase of heart rate (from 81 to 111/min), shortening of a-v nodal and atrial refraction (from 298 to 272 ms) as well as in shortening of stimuli cycle length revealing Wenckebach's point (from 324 to 291 ms). The Kent bundle refraction did not at the average change (333 and 324 ms), while in individuals great differences were observed. Generally, pharmacological blockade of the autonomic nervous system improves a-v nodal conduction, but in patients with WPW syndrome does not significantly effect on the accessory pathway.

[Effect of stimulation of adrenergic beta receptors on electrophysiologic properties of the bundle of Kent in patients with intermittent Wolff-Parkinson-White syndrome]. / Wplyw stymulacji receptorów beta-adrenergicznych na wlasciwosci elektrofizjologiczne peczka Kenta u chorych z intermitujacym zespolem Wolffa-Parkinsona-White'a.

In 15 patients with intermittent ventricular preexcitation symptoms the effect of intravenously administered dobutamine (10 mcg/kg b.w./min) on the ecg tracing, effective atrial, a-v nodal and Kent bundle refractions as well as the incidence of cardiac arrhythmias were assessed basing on results of the electrophysiologic examination. Pharmacological stimulation of the adrenergic system resulted in highly statistically significant shortening of examined refraction periods (p less than 0,02 for effective Kent bundle refraction and p less than 0,001 for the rest parameters) and improved the conduction via the accessory pathway as well as exacerbated cardiac arrhythmias.