Supraventricular tachycardia, right atrial pressure, atrial natriuretic peptide and polyuria--a necessary sequence?

A new score model to predict the inducibility of supraventricular tachycardia in patients with palpitation without documented electrocardiography

OBJECTIVE

Although electrophysiological study (EPS) is one of the most useful diagnostic approaches to detect the cardiac origin of palpitations, there is no clear indication for EPS in patients with palpitation in the absence of documented supraventricular tachycardia (SVT). In this study, we aimed to create a new SVT score model to detect the requirement of EPS in patients with palpitation without documented tachycardia.

METHODS

A total of 154 patients with palpitation were included in this study. To create the SVT score, we considered four main criteria with their subunits. They were severity, frequency, duration, and termination of the symptoms. EPS was performed on all the patients after their scoring assessment.

RESULTS

Median SVT score of induced tachycardia and non-induced patients was determined as 10 and 6 points, respectively; and it was found to be statistically significant; p<0.001. The cut-off value for inducibility was found to be 7.5 points through receiver operating characteristic curve analysis, (94.9% sensitivity, 92.1% specificity), and the area under the curve was determined to be 97.2 (94.8-99.5, p<0.001).

CONCLUSION

According to our new SVT score model, ≥8 points strongly correlates with the inducibility of SVT during EPS.

Symptoms in supraventricular tachycardia: Is it simply a manifestation of increased heart rate?

A significant proportion of patients in clinical practice may not have ECG recordings of the index tachycardia (non-documented SVT), or only have recordings of limited diagnostic value. Despite the highly specified symptomatic and ECG diagnostic criteria, diagnosis and referral for ablation treatment is not always straightforward. Although ECG based diagnostic or treatment algorithms have been well defined in literature, we need a symptom based diagnostic algorithm or scoring system in patients with suspected supraventricular arrhythmia. Individual approaches with a high suspicion index and concerning the paroxysmal nature and post attack symptoms would help us to identify patients suffering from SVT in complex cases.

The effects of posture change and continuous positive airway pressure on cardiac natriuretic peptides in congestive heart failure

We studied changes in the peripheral plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in seven patients with congestive heart failure (CHF) during four 1-h protocols during which patients maintained either an upright or a supine posture with or without nasal continuous positive airway pressure therapy (N-CPAP) at a pressure of 10 cm H2O (FIO2 = 0.21). The mean plasma ANP concentration of patients increased significantly from baseline at the end of 1 h of recumbency (65.9 +/- 5.8 to 82.6 +/- 8.3 pg/mL (mean +/- standard error); p < 0.05). This increase was prevented by concomitant N-CPAP therapy (72.1 +/- 8.0 to 61.0 +/- 8.8 pg/mL; p = NS). The mean level of ANP decreased significantly (71.9 +/- 9.0 to 62.5 +/- 8.0 pg/mL; p < 0.05) while patients simply maintained an upright posture. A significant reduction was also observed when patients remained upright with accompanying N-CPAP (72.6 +/- 10.9 to 54.6 +/- 4.3 pg/mL; p < 0.05). There were no significant changes observed in the mean level of BNP for any of the protocols undertaken. We conclude that in patients with chronic CHF, (1) an increase in ANP concentration occurs with recumbency, and this can be prevented by N-CPAP therapy; (2) a decrease in ANP occurs with maintenance of an upright posture, and that this reduction may be augmented by N-CPAP; and (3) no net change in BNP concentration occurs with either posture change or N-CPAP.