Publications

BACKGROUND

Because the His bundle is intrinsic to the circuit in orthodromic reciprocating tachycardia and remote from that of atrioventricular nodal reentrant tachycardia (AVNRT), pacing the His bundle during supraventricular tachycardia (SVT) may be useful to distinguish these arrhythmias.

OBJECTIVE

The purpose of this study was to test the hypothesis that His overdrive pacing (HOP) would affect SVT immediately for orthodromic reciprocating tachycardia and in a delayed manner for AVNRT.

METHODS

Once SVT was induced, HOP was performed by pacing the His bundle 10-30 ms faster than the SVT cycle length. The maneuver was determined to have entered the tachycardia circuit when a nonfused His-capture beat advanced or delayed the subsequent atrial electrogram by ≥10 ms or when the tachycardia was terminated. The number of beats required to enter each tachycardia with HOP was recorded.

RESULTS

HOP was performed during 66 SVTs (26 atrioventricular reciprocating tachycardia [AVRT] and 40 AVNRT). Entry into the tachycardia within 1 beat had sensitivity of 92%, specificity of 92%, positive predictive value (PPV) of 89% and negative predictive value (NPV) of 95% to confirm the diagnosis of AVRT. A cutoff ≥3 beats to enter the circuit had sensitivity of 90%, specificity of 92%, PPV of 95% and NPV of 86% to confirm the diagnosis of AVNRT. HOP had sensitivity, specificity, PPV, and NPV of 100% for distinguishing septal AVRT from atypical AVNRT.

CONCLUSION

HOP during SVT is a novel technique for distinguishing orthodromic reciprocating tachycardia from AVNRT. It can reliably distinguish between these arrhythmias with high sensitivity and specificity.

UNLABELLED

Endothelin-1 (ET-1) acts on endothelial cells to enhance mechanical stimulation-induced release of adenosine triphosphate (ATP), which in turn can act on sensory neurons innervating blood vessels to contribute to vascular pain, a phenomenon we have referred to as stimulus-dependent hyperalgesia (SDH). In the present study, we evaluated the role of the major classes of ATP release mechanisms to SDH: vesicular exocytosis, plasma membrane-associated ATP synthase, ATP-binding cassette transporters, and ion channels. Inhibitors of vesicular exocytosis (ie, monensin, brefeldin A, and bafilomycin), plasma membrane-associated ATPase (ie, oligomycin and pigment epithelium-derived factor peptide 34-mer), and connexin ion channels (carbenoxolone and flufenamic acid) but not ATP-binding cassette transporter (ie, dipyridamole, nicardipine, or CFTRinh-172) attenuated SDH. This study reports a role of ATP in SDH and suggests novel targets for the treatment of vascular pain syndromes.

PERSPECTIVE

ET-1 acts on endothelial cells to produce mechanical stimulation-induced hyperalgesia. Inhibitors of 3 different ATP release mechanisms attenuated this SDH. This study provides support for a role of ATP in SDH and suggests novel targets for the treatment of vascular pain syndromes.

CONTEXT

Most patients will lose decision-making capacity at the end of life. Little is known about the quality of care received by patients who have family involved in their care.

OBJECTIVES

To evaluate differences in the receipt of quality end-of-life care for patients who died with and without family involvement.

METHODS

We retrospectively reviewed the charts of 34,290 decedents from 146 acute and long-term care Veterans Affairs facilities between 2010 and 2011. Outcomes included: (1) palliative care consult, (2) chaplain visit, and 3) death in an inpatient hospice or palliative care unit. We also assessed "do not resuscitate" (DNR) orders. Family involvement was defined as documented discussions with the health care team in the last month of life. We used logistic regression adjusted for demographics, comorbidity, and clustered by facility. For chaplain visit, hospice or palliative care unit death, and DNR, we additionally adjusted for palliative care consults.

RESULTS

Mean (SD) age was 74 (±12) years, 98% were men, and 19% were nonwhite. Most decedents (94.2%) had involved family. Veterans with involved family were more likely to have had a palliative care consult, adjusted odds ratio (AOR) 4.31 (95% CI 3.90-4.76); a chaplain visit, AOR 1.18 (95% CI 1.07-1.31); and a DNR order, AOR 4.59 (95% CI 4.08-5.16) but not more likely to die in a hospice or palliative care unit.

CONCLUSION

Family involvement at the end of life is associated with receipt of palliative care consultation and a chaplain visit and a higher likelihood of a DNR order. Clinicians should support early advance care planning for vulnerable patients who may lack family or friends.