Coadministration of flecainide acetate and sotalol during pregnancy: lack of teratogenic effects, passage across the placenta, and excretion in human breast milk.
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Adult↗
Biomedical subjects
A Pisapia
Publications and source records attributed to A Pisapia.
Intrinsic and extrinsic sinus node dysfunction: diagnostic problems.
Based on clinical and experimental experience, pacemaker dysfunction in sick sinus syndrome can be differentiated into intrinsic and extrinsic. Sinus node activity is characterized electrophysiologically by automaticity, recovery and sinoatrial conduction. The automaticity of the sinus pacemaker cell groups and sinus recovery can be differentiated properly under experimental conditions. Studies of the electrophysiological characteristics have shown the basic functional parameters to be normal in extrinsic-autonomic sinus dysfunction. Diagnosis is either based on clinical observation or on the data of Holter monitoring, the electrophysiological methods being inadequate for diagnosing this neurovegetative form of sick sinus syndrome. On the other hand, intrinsic sinus dysfunction can be diagnosed by electrophysiological tests. If completed by complex pharmacological studies, in this organic form of sick sinus syndrome, even the severity of the intrinsic injuries can be assessed quantitatively. The above division provides a basis for selection and evaluation of the differential diagnostic procedures, while information on the aetiopathology of sinus dysfunction and on the degree of the functional injuries of the electrophysiological structure of the heart provides an adequate basis for therapy.
Adult↗
Sino-atrial dissociation: evidence by intracardiac recordings in man and by microelectrode studies on isolated rabbit atrium.
The electrophysiologic mechanisms of sinus dysfunction have recently been determined by direct recordings of the sinus node electrogram. The association of various degrees of abnormalities in the formation of the impulse within the sinus node and of sinoatrial conduction block, represents the pathophysiological substrate of the mechanism of sinus node dysfunction. The purpose of this work is to present clinical and experimental data supporting the concept of sinus node isolation. In our clinical case, the sinus node was probably intact despite aspects of sinus node dysfunction on the surface ECG. Sinus node electrograms were recorded with a sinoatrial conduction time of 100 ms (normal values in our laboratory: 83 ms +/- 38 ms). Atrial mapping demonstrated that the area depolarized by the sinus node involved a 2 cm2 zone surrounding it. This perisinusal activity could not be recorded on the surface ECG. Both exit and entry blocks in the sinus node were demonstrated. Our experimental data showed a total desynchronization between the electrical activity of the sinus node and that of the atrium under hypoxic conditions. Both types of cases demonstrated that an atrial dysrhythmia was coexisting with regular sinus activity. From these data we concluded that a sinus node free from any pathological involvement could be associated with severe symptoms of sinus node dysfunction on the surface ECG.
Animals↗
[Diagnostic problems in the physiopathological characterization of sinus dysfunction].
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Animals↗
[Intra-sinus echo: demonstration using direct intracavitary recording of the sinus potential].
The authors searched for intra-sinusal echos during electrophysiological investigation of 53 patients (41 men, 12 women, average age: 61 +/- 12 years). Cycles of sinus echos were recorded in 8 patients (15 per cent). The period during which sinus echos could be recorded was 125 ms (average 40.6 +/- 34 ms). Indirect assessment of sinus node function in patients with sinus echos was normal (corrected sinus node recovery time, estimated atrio-sino atrial conduction times using Narula's technique). A valid and reproducible direct recording of the sinus node potential was only possible in one patient. In this case the echo cycles were provoked by stimulation periods of between 440 and 320 ms (echo zone of 120 ms). All the echos obtained were preceded by a sinus node potential with a different duration and morphology to that observed during basal sinus cycles (respective sino-atrial conduction times 105 and 115 ms). In this patient we were also able to induce sinus echos after a single extrastimulus during the spontaneous rhythm. the echo zone was 130 ms and with a shorter coupling interval (310 ms) two successive sinus echos were recorded. The demonstration of intrasinusal echos by direct recording of the sinus node potential supports the experimental data of Allessie and Bonke on isolated right atrial tissues of the rabbit. Improvements in the technique of endocavitary direct recording of the sinus node potential in man should complete this data by showing the possibility of sinoatrial tachycardias due to reentry.
Action Potentials↗