Chronic epicardial his bundle recordings in awake nonsedated dogs: A new method

Recording cardiac electrical potentials from the region of the bundle of His in the awake, nonsedated animal would allow a more physiologic evaluation of impulse transmission through the specialized atrioventricular conduction system than anesthetized preparations. We present a new technique to localize and record chronic His bundle potentials using standard electronic equipment which obviates the need for intravascular catheters or an atriotomy. Six mature and four immature mongrel dogs underwent a midline thoracotomy. The bundle of His electrogram was recorded from the right atrial epicardium alongside the noncoronary aortic cusp. A flexible tripolar electrode probe with 3 mm interelectrode distance attached to a standard electronic recorder was used to localize the area of greatest His bundle impulse. Silver solder electrodes were sutured to the designated area and the wires were externalized to the back. Electrophysiologic measurements were made 1 to 20 weeks later to confirm the accuracy and stability of the His bundle electrogram. These recordings were comparable to the standard internal catheter measurements both before and during atrioventricular impulse interference caused by atrial pacing or pharmacologic intervention. Electrodes sutured to the designated area do not interfere with impulse conduction and allow stable His bundle recordings in all activity ranges in the chronic animal.     

Hemicraniectomy for Supratentorial Primary Intracerebral Hemorrhage: A Retrospective,Propensity Score Matched Study

Background and Purpose: Spontaneous supratentorial intracerebral hemorrhage (ICH) contributes disproportionately to stroke mortality, and randomized trials of surgical treatments for ICH have not shown benefit. Decompressive hemicraniectomy (DHC) improves functional outcome in patients with malignant middle cerebral artery ischemic stroke, but data in ICH patients is limited. We hypothesized that DHC would reduce in-hospital mortality and poor functional status (defined as modified Rankin scale ≥5) among survivors at 3 months, without increased complications. Methods: We performed a retrospective, case-control, propensity score matched study to determine whether hemicraniectomy affected outcome in patients with spontaneous supratentorial ICH. The propensity score consisted of variables associated with outcome or predictors of hemicraniectomy. Forty-three surgical patients were matched to 43 medically managed patients on ICH location, sex, and nearest neighbor matching. Three-month functional outcomes, in-hospital mortality, and in-hospital complications were measured. Results: In the medical management group, 72.1% of patients had poor outcome at 3 months compared with 37.2% who underwent hemicraniectomy (odds ratio 4.8, confidence interval 1.6-14). In-hospital mortality was 51.2% for medically managed patients and 16.3% for hemicraniectomy patients (odds ratio 8.5, confidence interval 2.0-36.8). There were no statistically significant differences in the occurrence of in-hospital complications. Conclusions: In our retrospective study of selected patients with spontaneous supratentorial ICH, DHC resulted in lower rate of in-hospital mortality and better 3-month functional status compared with medically managed patients. A randomized trial is necessary to evaluate DHC as a treatment for certain patients with spontaneous supratentorial ICH.