The incidence and severity of cutaneous burns following external DC cardioversion

Impact of Defibrillator Electrode Placement on Outcome of Electrical Cardioversion of Atrial Fibrillation: A Pilot Observational Study

BACKGROUND

Anterior-posterior electrode placement is preferred in electrical cardioversion of atrial fibrillation. However, the optimal anterior-posterior electrode position in relation to the heart is not studied.

METHODS AND RESULTS

We performed a prospective observational study on patients presenting for cardioversion of atrial fibrillation. Electrodes were placed in the anterior-posterior position and shock was delivered in a step-up approach (100 J→200 J→360 J). Fluoroscopic images were obtained, and distances were measured from points A, midanterior electrode; and B, midposterior electrode, to midpoint of the cardiac silhouette. Patients requiring one 100 J shock for cardioversion success (group I) were compared with those requiring >1 shock/100 J (group II). Logistic regression was used to determine the impact of electrode distance on low energy (100 J) cardioversion success. Computed tomography scans from this cohort were analyzed for anatomic landmark correlation to the cardiac silhouette. Of the 87 patients included, 54 (62%) comprised group I and 33 (38%) group II. Group I had significantly lower distances from the mid-cardiac silhouette to points A (5.0±2.4 versus 7.4±3.3 cm; P<0.001) and B (7.3±3.0 versus 10.0±3.8 cm; P=0.002) compared with group II. On multivariate analysis, higher distances from the mid-cardiac silhouette to point A (odds ratio, 1.33 [95% CI, 1.07-1.70]; P=0.01) and B (odds rsatio, 1.24 [95% CI, 1.05-1.50]; P=0.01) were independent predictors of low energy (100 J) cardioversion failure. Based on review of computed tomography scans, we suggest that the xiphoid process may be an easy landmark to guide proximity to the myocardium.

CONCLUSIONS

In anterior-posterior electrode placement, closer proximity to the cardiac silhouette predicts successful 100 J cardioversion irrespective of clinical factors.

Complications of catheter ablation for ventricular tachycardia

With the increasing literature demonstrating benefits of catheter ablation for ventricular tachycardia (VT), the number of patients undergoing VT ablation has increased dramatically. As VT ablation is being performed more routinely, operators must be aware of potential complications of VT ablation. This review delves deeper into the practice of VT ablation with a focus on periprocedural complications.

Investigating the efficacy of chest pressure for direct current cardioversion in atrial fibrillation: a randomised control trial protocol (Pressure-AF)

INTRODUCTION

Atrial fibrillation (AF) is the most common sustained arrhythmia worldwide. Direct current cardioversion is commonly used to restore sinus rhythm in patients with AF. Chest pressure may improve cardioversion success through decreasing transthoracic impedance and increasing cardiac energy delivery. We aim to assess the efficacy and safety of routine chest pressure with direct current cardioversion for AF.

METHODS AND ANALYSIS

Multicentre, double blind (patient and outcome assessment), randomised clinical trial based in New South Wales, Australia. Patients will be randomised 1:1 to control and interventional arms. The control group will receive four sequential biphasic shocks of 150 J, 200 J, 360 J and 360 J with chest pressure on the last shock, until cardioversion success. The intervention group will receive the same shocks with chest pressure from the first defibrillation. Pads will be placed in an anteroposterior position. Success of cardioversion will be defined as sinus rhythm at 1 min after shock. The primary outcome will be total energy provided. Secondary outcomes will be success of first shock to achieve cardioversion, transthoracic impedance and sinus rhythm at post cardioversion ECG.

ETHICS AND DISSEMINATION

Ethics approval has been confirmed at all participating sites via the Research Ethics Governance Information System. The trial has been registered on the Australia New Zealand Clinical Trials Registry (ACTRN12620001028998). De-identified patient level data will be available to reputable researchers who provide sound analysis proposals.

Cardioversion of Atrial Fibrillation with Acupuncture

Background: Atrial fibrillation, the most commonly treated arrhythmia, results in significant symptom burden, increased stroke risk, and costs 26 billion dollars annually in the United States alone. Maintaining sinus rhythm is often preferred, but current interventions have limitations and are associated with adverse effects. There are data suggesting that acupuncture can have a beneficial effect on maintaining sinus rhythm as well as limited data suggesting it can help convert atrial fibrillation to sinus rhythm in the acute setting. Case: An 82-year-old woman with history of heart failure with preserved ejection fraction as well as paroxysmal atrial fibrillation developed atrial fibrillation with rapid ventricular response during a hospitalization for acute exacerbation of heart failure and gastrointestinal bleeding. Given success in converting supraventricular tachycardia using ear Shen Men in a prior case as well as limited data suggesting a benefit of acupuncture in acute atrial fibrillation, acupuncture was utilized in the management of the acute atrial fibrillation. Acupuncture was initiated 4 hours after the arrhythmia began and a total of 8 ear points (4 each side) as well as bilateral pericardium 6 points were utilized. Results: Atrial fibrillation converted to sinus rhythm before the last needle was placed and the patient had no recurrence of atrial fibrillation throughout the remainder of her stay. Conclusions: Acupuncture appears to be solely responsible for the conversion of atrial fibrillation to sinus rhythm in this case, as no β-blockers, calcium channel blockers, or antiarrhythmic medicines were administered before the return to sinus rhythm. The antiarrhythmic effect noted may be from centrally mediated autonomic effects or additional mechanisms. Further study will help to define the role of acupuncture in the management of acute arrhythmias.

Spontaneous torsade de pointes and ventricular fibrillation in a dog during pacemaker implantation

Torsade de pointes is an unusual complication seen in dogs during pacemaker implantation, although ventricular fibrillation has been previously reported. This case report describes torsade de pointes in a dog during pacemaker implantation that degenerated into ventricular fibrillation and discusses the possible contributory factors. It also illustrates the relevance of a pre-emptive resuscitation plan and how this might have affected the outcome in the patient.

External versus internal cardioversion for atrial fibrillation: a meta-analysis of randomized controlled trials

BACKGROUND

Patients with atrial fibrillation (AF) often require rhythm control strategy for amelioration of symptoms. It is unclear if there is any difference between external cardioversion (ECV) and internal cardioversion (ICV) for successful conversion of AF to normal sinus rhythm.

METHODS

We performed a meta-analysis of published randomized controlled trials (RCTs) evaluating success of cardioversion using ECV versus ICV.

RESULTS

In the pooled analysis of 5 RCTS, there was no difference in success of cardioversion using ECV versus ICV (OR 1.69, 95% CI 0.24-11.83, p = 0.6). In the subgroup analysis, there was no difference between ECV and direct electrode ICV (OR 0.41, 95% CI 0.09-1.83, p = 0.24). However, ECV was significantly better compared with ICV using ICD (OR 11.97, 95% CI 1.87-76.73, p = 0.009).

CONCLUSIONS

There was no difference between ECV versus ICV in effectiveness for termination of AF. Larger well-designed randomized controlled trials are needed to confirm our findings.

Randomized trial comparing the effectiveness of internal (through implantable cardioverter defibrillator) versus external cardioversion of atrial fibrillation

PURPOSE

When patients with implantable cardioverter defibrillators (ICD) develop symptomatic atrial fibrillation (AF), external direct current cardioversion (EDCCV), as well as internal cardioversion using their ICD, are the options available. It is currently unknown which of these two methods are more effective. We compared the effectiveness of EDCCV versus internal cardioversion to terminate AF in patients with a single-coil ICD.

METHODS

This randomized controlled trial (clinicaltrial.gov NCT03164395) enrolled consecutive patients with a single-coil ICD that presented with symptomatic AF of less than 1-year duration. They received either the maximum energy internal shock through the ICD or an EDCCV using transcutaneous pads of 200 J. The primary endpoint was a successful conversion to sinus rhythm after one shock. Crossover was permitted if the first shock was unsuccessful.

RESULTS

Thirty-one patients were enrolled in the study, including 16 in the internal ICD cardioversion group. The study included patients with a mean age of 59.5 ± 16.0 years, 41.9% females, median AF duration 1 month (interquartile range 1-3), 45.2% non-ischemic cardiomyopathies, mean EF 28.6 ± 16.0%, and 45.2% biventricular ICD. There were no significant differences in baseline clinical characteristics between the two groups. In the internal cardioversion group, 5/16 patients (31.3%) met the primary endpoint versus 14/15 (93.3%) in the EDCCV group, p < 0.001. All patients that failed the first shock were subsequently cardioverted externally.

CONCLUSION

Among patients with a single-coil ICD and symptomatic AF of less than 1 year, external direct current cardioversion is much more effective than internal shock through the ICD.

Third-degree burns associated with transcutaneous pacing

A 69-year-old severely obese diabetic woman developed nausea, vomiting and diarrhoea which caused multiple metabolic alterations leading to hypotension and bradycardia due to slow atrioventricular junctional rhythm. Transcutaneous pacing (TCP) was initiated and maintained until the underlying heart rate and blood pressure normalised. TCP gel pads were kept in place prophylactically after pacing was terminated. Gel pads remained attached to the anterior thorax and back for a total of 36 hours. During this time the patient developed third-degree burns at the side of gel pad attachment. With appropriate wound care and after a long hospitalisation, the patient was discharged in stable condition. This case demonstrates that prolonged use of TCP gel pads without frequent replacement may lead to third-degree burns. It also suggest that prophylactic use of TCP gel pads should be avoided.

Paddle Position and Contact Force: An Important Step to Check When Troubleshooting for Refractory Ventricular Fibrillation

Ventricular fibrillation (VF) is a lethal medical emergency that requires immediate defibrillation. VF is resistant when it persists after three or more defibrillator shocks. Successful defibrillation requires depolarisation of a critical mass of myocardium. Several variables, such as the length of time in VF, body type, total energy used, and energy waveform have been reported to be associated with the success rate of defibrillation. Correct paddle position and good contact force to create an adequate current flow through the heart is essential for defibrillation. We report a patient who developed VF because of acute myocardial infarction that was resistant to a total of 13 shocks. The cause of shock-resistant VF was diagnosed by noticing the skin marks caused by the defibrillator paddle that indicated incorrect paddle position and inadequate paddle force. By checking the skin marks, an emergency physician could make a correct diagnosis within a few seconds and save a patient.

Hands-on defibrillation: theoretical and practical aspects of patient and rescuer safety

Defibrillators are used to treat many thousands of people each year using very high voltages, but, despite this, reported injuries to rescuers are rare. Although even a small number of reported injuries is not ideal, the safety record of the defibrillator using the current protocol is widely regarded as being acceptable. There is increasing evidence that clinical outcome is significantly improved with continuous chest compressions, but defibrillation is a common cause of interruptions; even short interruptions, such as those associated with defibrillation, may detrimentally affect the outcome. This has led to discussions regarding the possibility of continuing chest compressions during defibrillation; a process involving a rescuer working in close proximity to voltages of up to 5000 V. Not only do voltages of this magnitude have significant implications for the rescuer performing chest compressions, but there are also risks to other rescuers in the proximity, the patient and other bystanders. Clearly any deviation from accepted practice should only be undertaken following careful consideration of the risks and benefits to the patient, rescuers and others. This review summarises the physical principles of electrical risk and identifies ways in which these could be managed. In doing so, it is hoped that in future it may be possible to deliver continuous and safe manual chest compressions during defibrillator discharge in order to improve patient outcome.

Burn progression secondary to cardioversion

Severe burns result in a profound hypermetabolic response. Catecholaminergic surges secondary to the burn injury itself, particularly if superimposed on premorbid cardiac disease, can result in cardiac arrhythmias. If unstable, these cardiac rhythm disturbances necessitate immediate cardioversion to regain normal sinus rhythm. Because of the high impedance at the skin-paddle interface, superficial cutaneous burns have been known to develop secondary to cardioversion. The authors describe a novel case of the subsequent local progression of a previously sustained superficial flame burn to full-thickness burn injury after cardioversion.

A multicenter, open-label study of vernakalant for the conversion of atrial fibrillation to sinus rhythm

BACKGROUND

The efficacy and safety of vernakalant, a relatively atrial-selective antiarrhythmic agent, in converting atrial fibrillation (AF) to sinus rhythm (SR) were evaluated in this multicenter, open-label study of patients with AF lasting >3 hours and < or =45 days (RCT no. NCT00281554).

METHODS

Adult patients with AF and an indication for conversion to SR received a 10-minute intravenous infusion of vernakalant (3 mg/kg). If after a 15-minute observation period AF was present, a second 10-minute infusion of intravenous vernakalant (2 mg/kg) was given. The primary efficacy end point was the proportion of patients with recent-onset AF (AF lasting >3 hours to < or =7 days) who converted to SR within 90 minutes of the start of the first infusion. Safety evaluations included vital signs, telemetry and Holter monitoring, 12-lead electrocardiography, clinical laboratory tests, physical examinations, and adverse events (AEs).

RESULTS

A total of 236 hemodynamically stable patients with AF received intravenous vernakalant. Among them, 167 (71%) had recent-onset AF and were eligible for the primary efficacy end point. Vernakalant rapidly converted recent-onset AF to SR in 50.9% of patients, with a median time to conversion of 14 minutes among responders. The most common AEs were dysgeusia, sneezing, and paresthesia. These occurred at the time of vernakalant infusion, were transient, and resolved spontaneously. Ten patients (4.2%) discontinued vernakalant treatment because of AEs, most commonly (in 4 of 10) hypotension. There were no episodes of torsades de pointes, ventricular fibrillation, or sustained ventricular tachycardia.

CONCLUSIONS

Vernakalant rapidly converted recent-onset AF to SR, was well tolerated, and may be a valuable therapeutic alternative for reestablishing SR in patients with recent-onset AF.

The effects of concentric ring electrode electrical stimulation on rat skin

Surface electrodes are commonly used electrodes clinically, in applications such as functional electrical stimulation for the restoration of motor functions, pain relief, transcutaneous electrical nerve stimulation, electrocardiographic monitoring, defibrillation, surface cardiac pacing, and advanced drug delivery systems. Common to these applications are occasional reports of pain, tissue damage, rash, or burns on the skin at the point where electrodes are placed. In this study, we quantitatively analyzed the effects of acute noninvasive electrical stimulation from concentric ring electrodes (CRE) to determine the maximum safe current limit. We developed a three-dimensional multi-layer model and calculated the temperature profile under the CRE and the corresponding energy density with electrical-thermal coupled field analysis. Infrared thermography was used to measure skin temperature during electrical stimulation to verify the computer simulations. We also performed histological analysis to study cell morphology and characterize any resulting tissue damage. The simulation results are accurate for low energy density distributions. It can also be concluded that as long as the specified energy density applied is kept below 0.92 (A2/cm4.s(-1)), the maximum temperature will remain within the safe limits. Future work should focus on the effects of the electrode paste.

Electrical cardioversion

External electrical cardioversion was first performed in the 1950s. Urgent or elective cardioversions have specific advantages, such as termination of atrial and ventricular tachycardia and recovery of sinus rhythm. Electrical cardioversion is life-saving when applied in urgent circumstances. The succcess rate is increased by accurate tachycardia diagnosis, careful patient selection, adequate electrode (paddles) application, determination of the optimal energy and anesthesia levels, prevention of embolic events and arrythmia recurrence and airway conservation while minimizing possible complications. Potential complications include ventricular fibrillation due to general anesthesia or lack of synchronization between the direct current (DC) shock and the QRS complex, thromboembolus due to insufficient anticoagulant therapy, non-sustained VT, atrial arrhythmia, heart block, bradycardia, transient left bundle branch block, myocardial necrosis, myocardial dysfunction, transient hypotension, pulmonary edema and skin burn. Electrical cardioversion performed in patients with a pacemaker or an incompatible cardioverter defibrillator may lead to dysfunction, namely acute or chronic changes in the pacing or sensitivity threshold. Although this procedure appears fairly simple, serious consequences might occur if inappropriately perfformed.

Incidencia de las alteraciones cutáneas secundarias a la cardioversión eléctrica externa

External electrical cardioversion is a technique basically used as treatment of choice in supraventricular arrhythmias, atrial fibrillation standing out for its frequency. This procedure consists in the application of one or several synchronized electrical discharges through the patient's chest to revert cardiac rhythm to sinus rhythm. One of the complications is generally the appearance of the skin alterations, pain or intense local heat. The objectives of this study were to describe the skin lesions that appeared after an external electrical cardioversion procedure and to evaluate the information received by the patients on discharge. A descriptive study was conducted, using a sample of 68 patients who underwent cardioversion between January 1 and December 30 1, 2004. Mean age was 62.71 years, of which 76.5% were males diagnosed of atrial fibrillation in 82.4% of the cases. Erythema appeared in more than 80% of the cases, with the mean duration of 4.76 days. A total of 13.2% developed second-degree burn. Although 92.5% considered written information on the care after the procedure necessary, less than 11% had received it. It is concluded that the prevalence of the skin alterations after cardioversion is elevated, one of the causal factors being lack of information. There is a significant deficiency of knowledge on skin care after the procedure.

A randomised controlled trial of the effect of biphasic or monophasic waveform on the incidence and severity of cutaneous burns following external direct current cardioversion

OBJECTIVE

Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion. We designed a prospective randomised double-blinded controlled study to determine the effect of biphasic or monophasic waveform on the pain and inflammation occurring after elective cardioversion.

MATERIALS AND METHODS

One hundred and thirty nine patients undergoing elective DC cardioversion were randomised to receive monophasic (HP Codemaster XL; 100, 200, 300, 360, and 360 J) or biphasic (Welch Allyn-MRL PIC defibrillator; 70, 100, 150, 200, and 300 J) waveforms. Two hours after DC cardioversion, skin temperature, erythema index and sensory threshold to light and sharp touch was measured at the centre and edge of paddle sites. Visual analogue pain score (VAS) was recorded at 2 and 24 h.

RESULTS

There was significantly less pain following biphasic cardioversion as assessed by VAS at both 2 h (p < 0.001; 95% confidence intervals of difference of medians (CI) 0.2-0.8 cm) and 24 h (p = 0.004; 95% CI 0.0-0.4 cm). There was significantly less erythema in patients receiving biphasic cardioversion at the edge of the sternal site (p = 0.046; 95% CI 0.41-4.5). There was no difference in any other variable at any site between biphasic and monophasic cardioversion.

CONCLUSION

The use of a biphasic waveform for DC cardioversion reduces the inflammation and pain of burns as measured by erythema index and visual analogue scale.

[Comparison of two electrode positions in electrical cardioversion of atrial fibrillation]

OBJECTIVE

This study aims to compare effectiveness of electrical cardioversion (ECV) in patients with chronic atrial fibrillation (AF) according to the electrode positions: anteroapical (A-A) or anteroposterior (A-P). That which restores the sinus rhythm (SR) using the least energy is considered superior.

DESIGN

Observational study comparing two consecutive series of patients. SCOPE. Intensive Care Unit (ICU) of second level hospital.

PATIENTS AND METHODS

Out-patients in AF referred to the ICU for biphasic ECV. The first series began with position A-A and the second one with A-P, administering up to 3 shocks (150-200-200J), changing to the alternative position if SR was not achieved and administering 2 more shocks of 200J. Age, gender, weight, baseline heart disease, ejection fraction, left atrial size, AF time, baseline vital signs, antiarrhythmic medication, reversion to SR, number of shocks, energy used and side effects were analyzed and compared between both series. RESULTS. A total of 50 patients were treated in each group. The baseline characteristics were similar except for a greater percentage of women in group A-A. The anteroapical electrode position achieved SR with significantly fewer numbers of shocks and less energy, more frequently achieving reversion on the first shock.

CONCLUSIONS

We found greater effectiveness in the electrical cardioversion of the AF with the electrodes in the anteroapical position, that we recommend as first choice. If it is not effective, the A-P position should be attempted.

The effect of prophylactic topical steroid cream on the incidence and severity of cutaneous burns following external DC cardioversion

INTRODUCTION

Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion. We designed a prospective double-blinded controlled study to determine whether the application of steroid cream prior to cardioversion reduces their incidence and severity.

MATERIALS AND METHODS

Two hours before elective DC cardioversion, we applied betamethasone 0.1% cream or placebo cream over sternal and apical pad sites in 56 patients, with patients acting as their own controls. Two hours after cardioversion, a separate blinded observer measured the visual analogue pain score (VAS), sensory and pain detection thresholds, skin temperature and erythema index at sternal and apical pad sites.

RESULTS

The study had an 80% power to detect a 50% difference in VAS at 2 h, accepting an alpha error of 0.05. There was no difference between pain at 2 or 24 h, skin temperature, erythema index, sensory and pain detection thresholds at pad sites treated with steroid cream or control.

CONCLUSION

Topical betamethasone 0.1% cream applied 2 h before elective DC cardioversion is no more effective than placebo at reducing the pain and inflammation from cardioversion burns.

The effect of topical non-steroidal anti-inflammatory cream on the incidence and severity of cutaneous burns following external DC cardioversion

INTRODUCTION

Cutaneous burns are a common cause of morbidity following direct current (DC) cardioversion. We designed a study to determine whether the application of non-steroidal anti-inflammatory cream prior to cardioversion reduces their incidence and severity.

MATERIALS AND METHODS

Two hours before elective DC cardioversion, we randomised 55 patients to receive ibuprofen 5% cream or placebo cream over sternal and apical pad sites, with patients acting as their own controls. Two hours after cardioversion an independent blinded observer measured skin temperature, erythema index, and minimum sensory and pain detection thresholds at sternal and apical pad sites. Visual analogue pain score (VAS) for each site was recorded at 2 h and 24 h post-cardioversion.

RESULTS

There was a statistically significant difference between pain measured by VAS, skin temperature and pain detection threshold measured at pad sites with pre-applied ibuprofen 5% cream and those with pre-applied aqueous cream, after elective DC cardioversion.

CONCLUSION

Prophylactic application of topical ibuprofen 5% cream 2h prior to elective DC cardioversion reduces pain and inflammation. Consideration should be given to use of prophylactic application of topical ibuprofen as routine treatment for elective DC cardioversion.