H-Wave® Device Stimulation: A Critical Review

Pain treatments have historically centered on drugs, but an “opioid crisis” has necessitated new standards of care, with a paradigm shift towards multi-modal pain management emphasizing early movement, non-narcotics, and various adjunctive therapies. Electrotherapies remain understudied and most lack high-quality clinical trials, despite a desperate need for effective adjunctive options. A systematic search of human clinical studies on H-Wave® device stimulation (HWDS) was conducted as well as a comprehensive review of articles articulating possible HWDS mechanisms of action. Studies unrelated to H-Wave were excluded. Data synthesis summarizes outcomes and study designs, categorized as pre-clinical or clinical. Pre-clinical studies demonstrated that HWDS utilizes a biphasic waveform to induce non-fatiguing muscle contractions which positively affect nerve function, blood and lymph flow. Multiple clinical studies have reported significant benefits for diabetic and non-specific neuropathic pain, where function also improved, and pain medication usage substantially dropped. In conclusion, low- to moderate-quality HWDS studies have reported reduced pain, restored functionality, and lower medication use in a variety of disorders, although higher-quality research is needed to verify condition-specific applicability. HWDS has enough reasonable evidence to be considered as an adjunctive component of non-opioid multi-modal pain management, given its excellent safety profile and relative low cost. Level of Evidence: III.

Pulsed-Field Ablation in Ventricular Myocardium Using a Focal Catheter: The Impact of Application Repetition on Lesion Dimensions

Background - Pulsed-field ablation (PFA) is a rapid and nonthermal energy with higher selectivity to myocardial tissue in comparison to radiofrequency ablation (RFA). However, its effects on ventricular myocardium, and titration of lesion dimensions have not been well studied. This study examined the effect of PFA on ventricular myocardium, and the influence of application repetition on lesion dimensions. Methods - An 8Fr lattice catheter with a compressible 9 mm nitinol tip was used with a PFA generator (Affera Inc) applying a bipolar and biphasic waveform (±1.3-2.0 kV, 4 sec per application). We examined the impact of single applications (1x) vs four repetitive applications (4x) interspaced by 10 seconds. The latter was performed to determine whether repetitions of a similar electrical field can increase lesion dimensions. Experiments were performed in an in-vivo porcine model and a survival period of 24 hours (n=6) or 23±5.4 days (n=6) for evaluation of early and late histopathological effects. Results - PFA in ventricular myocardium showed repetition dependency. Acute lesion depth and volume increased from 5.6±1.43mm and 860±362mm 3 to 8.8±0.74mm and 2383±548mm 3 for 1x and 4x applications, respectively (P<0.001 for both comparisons). This effect was maintained in the chronic lesion phase with lesion depth and volume of 3.9±0.92mm and 655±286mm 3 compared with 7.3±0.83mm and 2170±488mm 3 , respectively (P<0.001 for both comparisons). Acute lesions showed well demarcated necrotic core without coagulation necrosis while chronic lesions showed tissue thinning with fibro-fatty replacement. Conclusions - PFA in ventricular myocardium exhibits repetition dependency as lesion dimension increases with consecutive applications of a similar electrical field.

Abstract 254: High Shock Efficacy and Algorithm Performance for a 150J Biphasic Waveform AED Used by Lay and BLS Responders During Out-of-hospital Cardiac Arrest

Introduction: Effective AED defibrillation of out of hospital cardiac arrest (OHCA) depends on the safe and effective identification of shockable rhythms, and on delivery of effective defibrillation energy. This report summarizes rhythm detection performance and shock efficacy during OHCA uses of Philips HeartStart Home and OnSite AEDs using non-escalating 150 J therapy. Methods: A convenience sample of 185 OHCA AED patient uses were reviewed by clinical experts. All analysis periods that resulted in AED rhythm advisories (Shock Advised or No Shock Advised) were annotated. Shockable rhythm categories include VF and polymorphic VT/flutter. Non-Shockable rhythm categories include normal sinus rhythm, other rhythms (e.g., atrial fibrillation/flutter, bradycardia, SVT, idioventricular, bundle branch block), and asystole. Intermediate rhythms (benefits of defibrillation are limited or uncertain) were not included. Post-shock rhythm was categorized as shockable, non-shockable, or undeterminable (rhythms corrupted by CPR artifact or pads removal within 5-s of shock delivery). Shock success was defined as conversion to a non-shockable rhythm within 5-s post-shock. Results: A total of 487 analysis periods resulted in AED rhythm advisories, with 175 annotated as Shockable and 312 Non-shockable. Sensitivity and specificity (n/N, Exact 95% CI) were 97.7% (171/175, 94.3%, 99.4%) and 100% (312/312, 98.8%, 100.0%) respectively. A total of 165 shocks were delivered to 100 patients with 5 undeterminable post-shock rhythms. The remaining 160 shocks were delivered to 156 Shockable rhythm episodes. All shock efficacy was 96.9% (155/160, 92.9%, 99.0%): 150 episodes converted to non-shockable rhythms after one shock (96.2% (150/156, 91.8%, 98.6%)); 154 after two shocks (98.7% (154/156, 95.4%, 99.8%)); and 155 after three shocks, the first two of which were undeterminable (99.4% (155/156, 96.5%, 100.0%)). The remaining episode had a failed first shock, followed by an undeterminable second shock, which was the last shock of the use. Conclusion: For these 150J fixed-energy AEDs, OHCA defibrillation is safe (100% specificity), and effective (97.7% sensitivity; 96.2% single shock effectiveness; 98.7% after two shocks; 99.4% after three shocks).

Orthogonal electrical cardioversion in atrial fibrillation refractory to biphasic shocks: a case series

Background Biphasic waveform shock has been established as the standard method for cardioversion of atrial fibrillation (AF). Depending on various factors, standard electrical cardioversion for AF may be unsuccessful in some cases, even with biphasic shocks. Case summary We report the safety and efficacy of orthogonal electrical cardioversion (OECV) as an alternative in patients with paroxysmal AF refractory to standard biphasic electrical cardioversion after up to three subsequent shocks of increasing energy and/or two or three initial shocks with maximum energy of 200-Joules. Shocks were delivered with two external defibrillators via two sets of adhesive electrode pads to apply two perpendicular electrical vectors in a simultaneous-sequential mode in antero-lateral and antero-posterior configuration. Five patients, mean age 54.4 ± 11, three with hypertensive heart disease and a body mass index 27.2 ± 2 kg/m2. All individual mean impedance before OECV was 79 ± 5 Ω with a mean peak current applied of 22 ± 4.5 A. Restoration of sinus rhythm with OECV was achieved acutely and sustained in all five patients. No patients developed haemodynamic instability or thromboembolic events. Discussion Double simultaneous shocks in an orthogonal configuration could theoretically decrease the defibrillation threshold through the ability of sequential pulses applying a more efficient and uniform current density. OECV using lower/medium energy may be another useful rescue strategy in AF refractory to standard biphasic shocks.

An Evaluation of Hemostatic Abnormalities in Patients With Hemophilia According to the Activated Partial Thromboplastin Time Waveform

The usefulness of the waveform of activated partial thromboplastin time (APTT) in various diseases has been evaluated in recent years. The APTT waveform was examined in patients with hemophilia and patients positive for lupus anticoagulant (LA). The correlation with the FVIII activity was highest for the height of acceleration peak. The peak time of acceleration, velocity, and ½ fibrin formation, and the width of acceleration and velocity were significantly long and the height of acceleration was significantly low in patients with hemophilia. The height of velocity was significantly low in patients with hemophilia with inhibitor. There were no significant differences in the APTT waveform between patients with hemophilia and patients with LA, but the peak of acceleration and ½ fibrin formation were significantly longer and the height of acceleration and velocity were significantly lower in patients with hemophilia with inhibitor than in the patients with LA. Wave changes in the APTT were observed in all 22 patients positive for LA, while a biphasic waveform was observed in patients with hemophilia with FVIII activity <10.0%. The APTT waveform is useful for the analysis of hemostatic abnormalities in patients with hemophilia.