Heart Rate Variability Markers as Correlates of Survival in Recipients of Hematopoietic Cell Transplantation

OBJECTIVES

To assess pre-/post-transplantation changes in autonomic tone, as measured by heart rate variability (HRV), among patients undergoing hematopoietic cell transplantation (HCT) and to look at those changes as they relate to post-transplantation survival rates. 
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SAMPLE & SETTING

Data were derived from a sample of 27 English-speaking patients undergoing allogeneic or autologous HCT at Stanford University. 
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METHODS & VARIABLES

A survival analysis using the Kaplan-Meier estimator was employed to explore whether increased HRV would enhance survival probabilities over time among patients undergoing HCT.
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RESULTS

An increased probability of survival was significantly related to increases in two HRV indexes.

IMPLICATIONS FOR NURSING

HRV may be a useful predictor of mortality among patients undergoing HCT. Interventions deliverable by nurses could be used to enhance HRV for patients identified as being at risk for early mortality.

Ambulatory blood pressure results and heart rate variability in patients with premature ventricular contractions

BACKGROUND

The presence of premature ventricular contractions (PVCs) is a sign of arrhythmia and typically trigerred by over stimulation of the sympathetic nervous system. This study examined the relationships among PVCs, heart rate variability (HRV), and 24-hour ambulatory blood pressure (ABP) results.

METHODS

This observational clinical study evaluated a cohort of 100 consecutive patients (58 women and 42 men) with PVCs. The individuals were split into occasional (n = 50) and frequent (n = 50) PVCs groups. All Holter recordings were performed during a working day.

RESULTS

Daytime low-frequency power (LFP), daytime low frequency/high frequency (LF/HF), nighttime LFP, and nighttime LF/HF and 24-hour systolic blood pressure (SBP) were slightly higher in the frequent PVCs group (p = 0.046, p = 0.027, p = 0.038, p = 0.032, and p < 0.001, respectively). Hypertension, LF, LF/HF, 24-hour SBP were positively correlated with PVCs (r = 0.305, p = 0.002; r = 0.269, p = 0.007; r = 0.403, p < 0.001, respectively).

CONCLUSION

Frequent PVCs reflect dominance of the sympathetic system according to the results of Holter recordings. This study showed that PVC had a significant association with high blood pressure values. Assessment of ABP and HRV in patients with PVCs is part of a comprehensive approach to the assessment of cardiovascular regulation.