Acute effects of inhaled iloprost on intracardiac conduction in patients with pulmonary arterial hypertension

BACKGROUND

Pulmonary arterial hypertension (PAH) is a severe, life-threatening disorder despite the availability of specific drug therapy. A lack of endogenous prostacyclin secondary to downregulation of prostacyclin synthase in PAH may contribute to vascular pathologies. Therefore, prostacyclin and its analogs including inhaled iloprost may decrease pulmonary arterial pressure and ventricular pressure.

METHODS

Here, we studied that acute effects of iloprost used in pulmonary vasoreactivity testing on the intracardiac conduction system in patients with PAH. A total of 35 (15 idiopathic PAH, 20 congenital heart disease) patients with PAH were included in this prospective study. Patients were divided into two groups: 22 patients with negative pulmonary vasoreactivity in group 1 and 13 with positive pulmonary vasoreactivity in group 2. Electrophysiological parameters including basic cycle length, atrium-His (AH) interval, His-ventricle (HV) interval, PR interval, QT interval, QRS duration, Wenckebach period, and sinus node recovery time (SNRT) were evaluated before and after pulmonary vasoreactivity testing in both groups.

RESULTS

The AH interval (81 [74-93]; 80 [65.5-88], p = 0.019) and SNRT (907.7 ± 263.4; 854.0 ± 288.04, p = 0.027) was significantly decreased after pulmonary vasoreactivity testing. Mean right atrium pressure was found to be correlated with baseline AH (r = 0.371, p = 0.031) and SNRT (r = 0.353, p = 0.037).

CONCLUSION

Inhaled iloprost can improve cardiovascular performance in the presence of PAH, primarily through a reduction in right ventricular afterload and interventricular pressure. Decreased pressure on the interventricular septum and ventricles leads to conduction system normalization including of the AH interval and SNRT due to resolution of inflammation and edema.

Electrophysiocardiogram: For the first time EPCG has been recorded on human body surface

Since ECG was invented in 1903, this is the first time in history that a full information multi-band and multi-linear electrophysiological cardiogram has been used to successfully scan and record on the human body surface. Since it is able to record various multi-band, multi-track linear electric signals of cardiac electrophysiological activities that correspond to different regions of the entire heart, it has thus been denominated as "electrophysiocardiogram" (EPCG). A traditional ECG is always represented by a characteristic wave form, which resembles a string. For a long period of time, ECG has had a lot of mysteries surrounding it, it maybe because ECG has a lot of mixed signals buried in such convolutionary forms, which limits the amount of the signals that are discernable and determinable. For the first time, the EPCG technology has allowed cardiac signals to be convoluted into the linear wave form, which is then processed through various new approaches featuring multiple frequency bands, multiple dimensions and multiple patterns, and consequentially recorded as the following types of signals within the ranges of P wave and T wave: multiple frequency band signals, signals of different regions and different locations, forward waves and negative waves. Therefore, EPCG may help to solve many puzzling scientific questions regarding heart, such as exactly how many electric signals are involved in heart excitation, pacing, conduction and action, as well as many other intriguing questions about heart, and thus would become a very helpful tool in clinical practice.

Retrograde fast pathway ablation with the EnSite NavX mapping system for slow-fast atrioventricular node reentrant tachycardia and a prolonged PR interval during sinus rhythm

An 84-year-old male had experienced palpitations. He was transported to our hospital for treatment of palpitations. A 12-lead electrocardiogram (ECG) showed regular tachycardia with a wide QRS complex of 153 bpm, and the P wave was not clear. The ECG after the tachycardia stopped showed a sinus rhythm, and there was a prolonged PR interval of 312 ms and complete right bundle branch block. We recorded a prolonged AH interval (235 ms) in electrophysiology study (EPS). As for the St-A interval (185 ms) by consecutive pacing from the right ventricular apex, it was short in comparison with the anterograde conduction. As a result of detailed EPS, we diagnosed the tachycardia as slow-fast atrioventricular nodal reentrant tachycardia. The anterograde conduction depended on the slow pathway (SP), and the fast pathway (FP) was considered to have only retrograde conduction. It was thought that a complete atrioventricular block been caused by the SP ablation. Therefore we carried out FP ablation with three-dimensional computed tomography and the EnSite NavX mapping system (St. Jude Medical, St Paul, MN, USA), which was superior in space resolution power, and were able to effect a radical cure without complications.