[The signal-averaged ECG in long-term monitoring of patients with fulminant myocarditis]. / Prumerované EKG v dlouhodobém sledování nemocného s fulminantní myokarditidou.

A case of a 24 year-old patient with fulminant myocarditis is described. The lymphocytic myocarditis was proved by endocardial biopsy. The patient had been followed for 15 months clinically, by transthoracic ultrasound and by the signal averaged ECG. The clinical and ultrasound parameters of the left ventricular systolic dysfunction subsided within 6 months, STT changes on the routine 12-lead ECG within 2 months. On the signal-averaged ECG, changes were observed in both the time and in the frequency domain. When the results of the initial examination (6 weeks after the beginning of the disease) were compared with the examination at the 7th month of the disease there was a prolongation of the QRS duration (from 95 ms to 104 ms), prolongation of the duration of the filtered ECG below 40 microV (from 21.5 to 36.2 microV) and the decrease of the total sum of the potential in the terminal part of the QRS. Most apparent was the decrease in the total sum of the high-frequency components (filter 70-250 Hz) of the QRS (RMSt: from 53.3 microV to 37.9 microV at the same noise level). In contrast to the changes in the time domain parameters there was no tendency in improvement of the RMSt. In patients with myocarditis the signal averaged ECG may prove to be a suitable tool for the long-term follow-up of the subclinical structural abnormalities of the left ventricular wall.

[The role of the atrium and optimal values of AV intervals in sequentially paced patients]. / Sínový príspevek a optimální hodnota AV intervalu u sekvencne stimulovaných nemocných.

In 1995, 2249 dual chamber pacemakers were implanted in the Czech Republic. These pacemakers make it possible to set an optimal AV delay between the atrial and ventricular impulse. Although the optimization of the AV interval has its well defined physiologic advantages, it does not seem to be necessary in otherwise healthy individuals with a good atrial and ventricular function. In these patients the default value, usually about 170 ms, is acceptable. However, AV interval optimization--i.e. finding the interval at which the atrial contribution to ventricular filling is maximal--should be done in all patients with left ventricular dysfunction, indicated for pacing because of bradyarrhthmia. In this subset of patients, even a small improvement in ventricular filling is believed to be clinically useful. Moreover, it has been documented, that in some types of ventricular dysfunction the so-called "primary optimization" (i.e. optimization of the AV interval in patients, in whom the pacemaker is not indicated for bradyarrhthmia but for ventricular dysfunction that might be improved by AV interval optimization) may be clinically useful. It is the case in patients with hypertrophic obstructive cardiomyopathy, dilated cardiomyopathy with presystolic regurgitation and AV interval prolongation, and perhaps even in some patients with impairment of ventricular systolic function and substantial prolongation of the AV interval. Despite all that, optimization of the AV interval is not routinely performed because even the best available optimization procedures (stroke volume measurements at different AV intervals by aortic Doppler echography) is observer dependent, time-consuming and costly.

[Late ventricular potentials in patients with recurrent ventricular tachycardia after myocardial infarct]. / Pozdní komorové potenciály u nemocných s recidivující komorovou tachykardií po infarktu myokardu.

In 26 patients who had at least two documented attacks of persisting ventricular tachycardia for 48 hours or longer after a myocardial infarction and whose standard QRS complex during sinus rhythm was < or = 120 ms, the authors examined late ventricular potentials using an Arrhythmia Research Technology apparatus EPX 1200. Positive finding were obtained in 19 (73%) of the patients. The finding is comparable with data in the literature on the prevalence of late ventricular potentials in patients with recurrent persisting ventricular tachycardia after myocardial infarction.