Efficacy and economic benefits of a modified Valsalva maneuver in patients with paroxysmal supraventricular tachycardia

BACKGROUND A modified Valsalva maneuver(VM)has been suggested to be superior to the standard VM for conversion of paroxysmal supraventricular tachycardia(PSVT).AIM To evaluate the efficacy and economic benefits of a modified VM in Chinese patients.METHODS Patients with PSVT admitted to our center between October 2017 and September 2019 were randomly assigned to the modified and standard VM groups.Conversion via VM was performed up to three times.The primary outcome of the study was the success rate of PSVT conversion to sinus rhythm.The secondary outcomes included the incidence of adverse events,economic cost during the visit,and the degree of patient acceptance of the treatment.RESULTS Overall,361 patients were enrolled,with 180 allocated to the modified VM group and 181 to the standard VM group.Baseline characteristics were well matched in the groups.Overall,the modified VM group had higher success rates of PSVT conversion after single(47.78%vs 15.38%,P<0.001)and multiple(62.22%vs 19.78%,P<0.001)VM sessions.No significant differences in the incidences of adverse events and rates of patient acceptance were detected between the two groups(both P>0.05).Moreover,the economic cost of the clinic visit was significantly lower for the modified VM group than for the standard VM group(P<0.05).CONCLUSION The modified VM may confer both therapeutic and economic benefits as compared with the standard VM for conversion of PSVT.

CHANGES OF PLASMA ENDOTHELIN AND ATRIAL NATRIURETIC PEPTIDE DURING THE ONSET AND AFTER TERMINATION OF PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA

Radioimmunoassays were used to measure the concentration changes of plasma endothelin(ET) and atrial natriuretic peptide(ANP) during the onset and after termination of paroxysmal supraventricular tachycardia(SVT). 30 cases were reviewed and compansons with 42 normal subjects were made. There are very significant differences(P<0.0001) in the concentration changes of both plasma ET and ANP during the onset and 30 minutes after the termination of SVT. During the onset period of SVT. the plasma ET and ANP were markedly elevated and 30 minutes after its termination they were lowered significantly, but their concentrations were still 2-fold higher than ihose of the control group. As the biological effects of ANP and ET are antagonistic to each other. their parallel elevation and lowering of plasma concentrations during and.after the termination of SVT reveal that these 2 hormones parucipate in the pathophysiological process of SVT. This phenomenon is possibly one of the homeostatic regulatory functions in the organism.

Atypical Intrapartum Maternal Heart Rate Pattern in a Woman with Paroxysmal Supraventricular Tachycardia

Pregnant women show characteristic hemodynamics, and their heart rates ordinarily increase with uterine contractions during labor. Conversely, uterine contraction-associated decelerations of maternal heart rate (MHR) are rare. We present a pregnant woman with paroxysmal supraventricular tachycardia (PSVT) who exhibited intrapartum MHR deceleration pattern. We performed simultaneous fetal heart rate monitoring with an external ultrasound transducer and MHR monitoring with a tocogram during her parturition. She developed a PSVT exacerbation in the second stage of parturition. As revealed by cardiotocography, the MHR baseline abruptly declined at onset of uterine contractions during the active phase of labor. Recovery followed, and the contraction resolved. The tachycardia got prolonged as the labor advanced. Our patient exhibited the unusual, up-and-down changes of the MHR pattern associated with labor contractions. The etiology of the occurrence of uterine contraction-associated MHR decelerations was unclear in the present case. Continuous tracing to visually inspect MHR patterns during parturition is a simple method for examining real-time MHR status of patients treated within obstetric practice settings.

Bipolar Esophageal Electrocardiography by Using Standard Limb Leads

The ear-xiphisternum distance (EXD, the distance from the low edge of the ear to the xiphisternal basis in supine position) was used as a reference value for esophageal catheter insertion. ECGs recorded in the esophagus with bipolar electrocardiography using standard limb lead (ESLL) and conventional unipolar lead (ECUL) were compared. 112 patients with sinus rhythm and 76 patients during paroxysmal supraventricular tachycardia (PSVT) whose P-wave and QRS complex did not overlap were studied. The results suggested that in sinus rhythm the amplitude of the P-wave in ESLL was larger and the T-wave was smaller than in ECUL. During PSVT, the P-wave was much clear and higher in each lead of ESLL than that in ECUL. The ideal range of esophageal ECG recording was situated between the end of EXD and 6. 5 cm proximal to it.