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Biomedical subjects

F Walczak

Publications and source records attributed to F Walczak.

At least 55 records · Page 3Linked to original sources
PubMed1982

Noninvasive recording of His-Purkinje system [HPS] activity in man on beat-to-beat basis.

Since 1969 His bundle electrography has been used for diagnosis and for the study of cardiac electrophysiology. This method has employed the catheterization technique and has allowed the continuous recording of electrical activity of the specialized cardiac conduction system in every beat. Such investigation, because of its invasive nature, cannot be considered a routine test; it requires expensive instrumentation, it has physiological and technical limitations that include discomfort, a slight morbidity risk and a rather limited recorded area within the heart. In 1973 a method was developed for a noninvasive recording of the electrical activity within the P-R segment of the electrocardiogram measured from the body surface. This method which employs the signal averaging technique delivers even less medical information than intracardiac measurement. The shortcomings of this averaging method include inability to detect beat-to-beat changes in the true signal. Such a method is not useful in transient arrhythmia detection and a "short acting" drug influence examination. The technical approach to the beat-to-beat noninvasive recording of the HPS activation signal as measured from the body surface has been proposed. Using a specially positioned electrode system, a low noise multiple parallel input amplifier and a computer for sampling, processing and plotting of the measured signal, we have obtained an output curve corresponding to the continuous beat-to-beat HPS activity.

Adult↗
PubMedDate not supplied

Dilated cardiomyopathy in children: clinical course and prognosis.

The clinical profile of 19 patients with dilated cardiomyopathy ages 2-18 years (mean 13.4 +/- 4 years) was reviewed to detect any factors that might be predictive for their survival. Follow-up range from 5 to 105 months (mean 39 +/- 33 months). Routine treatment consisted of digitalis and diuretics: 14 patients received antiarrhythmics, 6 received vasodilators, and 12 were managed with immunosuppression. There were 12 survivors and 7 nonsurvivors: The 1-year mortality was 21.2% and the 2-year mortality 35.8%. All deaths were within first 2 years. Of the 12 patients who survived 2 years, a significant improvement was noticed in 9. In 3 patients tachycardia-induced cardiomyopathy was diagnosed, and abolition of supraventricular tachycardia was followed by improvement and regression of cardiomegaly. Endomyocardial biopsy was performed in 16 patients. Four with a histologic diagnosis of active myocarditis survived, and in 3 of them a considerable improvement was noticed. Of the 12 patients with nonspecific histologic findings, 6 died (p < 0.05). There were no significant differences between survivors and nonsurvivors for any of the following parameters: incidence of severe heart failure (NYHA class III-IV) and severe ventricular arrhythmias (Lown class III-V), relative heart volume, echocardiographic left ventricular diastolic diameter and shortening fraction, and the hemodynamic parameters of cardiac index, left ventricular ejection fraction, left ventricular end-diastolic pressure, and left ventricular end-diastolic volume index.

Adolescent↗
PubMedDate not supplied

[Emergency epicardial dissection of the accessory pathway in a patient with atrioventricular nodal reentrant tachycardia].

Diagnostic and therapeutic problems in 14 year old patient with concealed WPW syndrome were presented. Paroxysms of atrio-ventricular reentrant tachycardia 180-220/min were frequently recurring, usually with normal QRS pattern. Tachycardias often had to be terminated by intravenous administration of antiarrhythmic drugs. Long term treatment with various antiarrhythmic agents did not prevent recurrence of tachycardias but they became sustained and were recurring more often. Their other side effects manifested with sinus node disfunction and depression of the heart muscle. The electrophysiologic study revealed right anterior septal accessory pathway. Epicardial dissection of the accessory pathway was urgently performed. The control electrophysiologic study revealed no evidence of conduction through the accessory pathway. The patient did not require antiarrhythmic treatment. During the 12 months follow up no tachycardia occurred.

Adolescent↗
PubMedDate not supplied

[Multi-electrode mapping from thoracic surface in patients with Wolff-Parkinson-White syndrome].

Body surface potentials mapping is a new method of heart electric phenomena visualisation. Attempts of accessory conduction pathways localisation in 9 patients with overt and in 1 with concealed WPW syndrome are presented. In 4 pts the preexcitation with QRS complex > 120 ms was clearly seen, in next 4 individuals that symptom was less evident and in one case the retrograde conduction through the accessory pathway was hardly noticed. The isopotential maps allowed precise localisation of the accessory pathways ventricular insertion in all patients with QRS > 120 ms and in one with QRS < 120 ms. After successful dissection of accessory pathways, isopotential maps became normal. In patients with slight signs of preexcitation, noninvasive (transesophageal) or invasive atrial stimulation could improve the visibility of accessory pathways localisation.

Action Potentials↗