[Hemodynamic significance of atrio-ventricular sequence in the example of an observed case]. / Znaczenie hemodynamiczne sekwencji przedsionkowo-komorowej na przykladzie obserwowanego przypadku.

A case of a 62 year old man with chronic complete atrio-ventricular block but persistent electrical and mechanical atrial activity is presented. The patient was treated by ventricular pacing of the VVI type. During cardiac catheterization right atrium, right ventricle and pulmonary pressure were recorded at basal conditions; right ventricle contractility index and cardiac output were also estimated. An elevation of right atrial pressure simultaneously with a fall of right ventricle and pulmonary pressure were repeatedly observed. These changes were a consequence of atrio-ventricular sequence disorders resulting in un-coordination of atrial and ventricular contractions. Hemodynamic parameters were restored to the physiological range only during the chance appearance of normal atrio-ventricular sequence. The presented observations support the known fact that ventricular pacing in patients with complete atrio-ventricular block may lead to serious hemodynamic disturbances.

[Multi-site pace making for dilated cardiomyopathy]. / Wielomiejscowa (multisite) stymulacja serca u chorych z kardiomiopatia rozstrzeniowa.

Dual chamber pacing (DDD) has been reported to be effective in patients with dilated cardiomyopathy (DCM). Other works, however, show contradictory results. Deleterious effects resulting from desynchronization of the right and left ventricular contraction have been suggested. In patients with end-stage DCM and severe congestive heart failure multisite pacing may be associated with fast and sustained hemodynamic improvement.

[The role of prolonged cardiac pacing in management of secondary bradyarrhythmias based on personal experiences]. / Miejsce przewleklej stymulacji elektrycznej serca w leczeniu wtórnych bradyarytmii na podstawie wlasnych spostrzezen.

Three patients with bradyarrhythmia who were admitted to the Department for urgent pacemaker implantations are presented. The careful clinical evaluation revealed that these arrhythmias were remarkably secondary to underlying diseases (e.g. severe coronary heart disease, valvular defects). Surgical treatment applied in these cases (coronary bypass grafts, valve replacement) has resulted in successful outcome. We concluded that in some patients the pacemaker implantation alone, without heart surgery, would not be beneficial enough.

Plasma ANP and cyclic GMP levels versus left ventricular performance at different AV delays in AV sequential pacing.

Eleven resting patients with an implanted DDD pacemaker were studied. After 30 minutes of AV sequential pacing at a rate of 80 beats/min with three consecutive atrioventricular delays (AVDs; 100, 150, and 200 msec) peripheral venous blood was drawn for further analyses by specific radioimmunoassays of atrial natriuretic peptide (ANP) and the ANP second messenger, cyclic guanosine monophosphate (cGMP). Relative changes in left ventricular (LV) stroke volume following alterations of AVD were assessed by means of pulsed-Doppler echocardiography through measurement of LV outflow time-velocity integrals (TVI). The optimal AVD (oAVD) was defined in individual patients as that which was associated with the greatest TVI and with improvement over both other AVDs of more than 4%. The oAVD was found in nine patients. For these nine patients no significant differences in either plasma ANP or cGMP between various AVDs were observed. However, we found such differences with respect to values measured at oAVD; both ANP and cGMP levels were lowest at oAVD. Pooling together the data obtained in 11 patients at three AVDs, a positive correlation between ANP and cGMP levels was found (r = 0.7, P < 0.0001, n = 33). Moreover, changes of plasma ANP and cGMP induced by every AVD increment of 50 msec were also correlated (r = 0.6, P < 0.01, n = 22). It is concluded that in AV sequential pacing at rest plasma ANP reaches minimal levels at the AVD, which provides the best LV performance. Although levels of cGMP changed in parallel with those of ANP, low relative values of cGMP differences may limit the usefulness of cGMP assays in optimization of the AVD.