[The influence of ischemia provoked by dobutamine and exercise on presence of late potentials in patients after myocardial infarction]. / Wplyw przejsciowego niedokrwienia prowokowanego testem dobutaminowym i wysilkowym na obecnosc póznych potencjalów komorowych u chorych po zawale serca.

UNLABELLED: The aim of this study was to examine the influence of transient exercise- and dobutamine-induced myocardial ischemia on time domain parameters of signal-averaged ECG (SAECG) and presence of late potentials (LP) in patients after myocardial infarction (MI). The investigation covered 85 patients after healing of MI, divided into two groups. Group I (24 males and 2 females, mean age 56.8 +/- 6.4 yrs) had exercise-induced ischemia and group II consisted of 59 patients (51 males and 8 females, mean age 58.3 +/- 8.5 years) with ischemia provoked by the intravenous dobutamine stress-testing. In each patient 2-D echocardiography, 24-h ambulatory Holter ECG, coronary arteriography were performed before stress testing. The ischemia was proven by using Tc-99m MIBI myocardial perfusion and standard 12-lead ECG monitoring. Recordings of SAECG were registered at rest and during ischemia under influence of stress-testing. The following time-domain parameters of SAECG were analysed: the root-mean-square voltage of the last 40 and 50 ms of the filtered QRS complex (RMS40, 50), total time duration of filtered QRS (t-QRS) and duration of signal lower than 40 muV (LPD). LP were detected when two or three of following criteria's had been registered: RMS 40 < 20 muV, t-QRS > 114ms, LPD > 38s. There was no statistically significant differences in all time domain parameters of SAECG between records at the baseline and during ischemia in each study group. At the baseline LP have been registered in 11.5% and in 15% patients, respectively of group I and group II. On the top of ischemia during treadmill exercise stress-testing LP have been recorded in 27% subjects. Under influence of dobutamine-provoked ischemia LP have been registered in 25% patients. CONCLUSIONS: Exercise- and dobutamine-induced ischemia triggers development of LP in small grade in post-infarction patients.

[The influence of exercise and dobutamine-induced ischemia on the presence of late potentials in patients after myocardial infarction]. / Wplyw przejsciowego niedokrwienia mienia serca prowokowanego testem dobutaminowym i wysilkowym na obecnosc póznch potencjalów komorowych u chorych po zawale serca.

UNLABELLED: The aim of this study was to examine the influence of transient exercise- and dobutamine-induced myocardial ischemia on time domain parameters of signal-averaged ECG (SAECG) and presence of late potentials (LP) in patients after myocardial infarction (MI). The investigation covered 85 patients after healing of MI, divided into two groups. Group I (24 males and 2 females, mean age 56.8 +/- 6.4 yrs) had exercise-induced ischemia and group II consisted of 59 patients (51 males and 8 females, mean age 58.3 +/- 8.5 years) with ischemia provoked by the intravenous dobutamine stress-testing. In each patient 2-D echocardiography, 24-h ambulatory Holter ECG, coronary arteriography were performed before stress testing. The ischemia was proven by using Tc-99m. MIBI myocardial perfusion and standard 12-lead ECG monitoring. Recordings of SAECG were registered at rest and during ischemia under influence of stress-testing. The following time-domain parameters of SAECG were analysed: the root-mean-square voltage of the last 40 and 50 ms of the filters QRS complex (RMS40, 50), total time duration of filtered QRS (t-QRS) and duration of signals lower than 40 microV (LPD). LP were detected when two or three of following criterias had been registered: RMS 40 < 20 microV, t-QRS > 114 ms, LPD > 38 s. There was no statistically significant differences in all time domain parameters of SAECG between records at the baseline and during ischemia in each study group. At the baseline LP have been registered in 11.5% and in 15% patients, respectively of group I and group II. On the top of ischemia during treadmill exercise stress-testing LP have been recorded in 27% subjects. Under influence of dobutamine-provoked ischemia LP have been registers in 25% patients. CONCLUSION: Exercise- and dobutamine-induced ischemia triggers development of LP in small grade in post-infarction patients.

[The effect of long term use of amiodarone hydrochloride on time and frequency domain parameters of signal averaged electrocardiogram in patients with ischemia heart disease]. / Wplyw przewlekle stosowanego chlorowodorku amiodaronu na parametry czasowe i czestotliwosc elektrokardiogramu wysokiego wzmocnienia u chorych na chorobe niedokrwienna serca.

The aim of this study was to assess the influence of amiodarone hydrochloride on time- and frequency-domain parameters of signal-averaged electrocardiogram (SAECG) in patients with ischaemic heart disease (IHD). The study population consisted of 33 patients (18 female and 15 male), mean age 59.2 +/- 7.7. Amiodarone hydrochloride was orally used in the initial dose 600 mg/day for 10 days, and subsequently 200 mg/days for 6 weeks. Recording of SAECG and ambulatory Holter monitoring were made at baseline and in 10 day and after 6 weeks of therapy. The following time-domain parameters were analyzed: the root mean square voltage of the last 40 and 50 ms of the filtered QRS (RMS40 i RMS50), total time duration of filtered QRS (t-QRS) and duration of low amplitude signals < 40 microV in the terminal part of QRS (LPD). Late potentials (LP) were recognized when at least two from three criteria were fulfilled: 1) RMS40 < 20 microV, 2) t-QRS > 114 ms, 3) LPD > 38 ms. Frequency analysis of SAECG allowed to calculate the following parameters in logarithmic scale: energy spectrum > -60 dB (A) and decibel drop at 40Hz (Dd) and also in linear scale: area ratio 20-50/0-20Hz (Ar) and magnitude ratio (MR1-7). The values of RMS40 and RMS50 did not significantly change during amiodarone therapy. The obtained values of t-QRS were significantly longer after antiarrhythmic therapy, respectively 97.8 +/- 9.1 ms at the baseline, 102.1 +/- 10 ms after 10 days (p < 0.05), and 104.1 +/- 10.4 ms after 6 weeks (p < 0.005). Moreover the values of LPD did not significantly change after amiodarone treatment. At the baseline the presence of LP were observed in 3 (9%), after 10 days were recorded in 8 (24%), and after 6 weeks in 7 (22%) cases. Only in one case the LP were observed during the whole antiarrhythmic therapy. Moreover, amiodarone hydrochloride did not statistically significant change frequency-domain parameters in logarithmic scale and in linear scale.