The Introduction of a New Service for DCCV for AF in a District
The timing and effectiveness of a new protocol for organising direct current cardioversion (DCCV) for patients with atrial fibrillation (AF) was compared with the existing system in a medium-sized district general hospital in the United Kingdom. The new protocol comprised a monthly dedicated DCCV list in the operating theatres, with an anaesthetist and an Operating Department Assistant providing anaesthesia, and cardiology medical staff performing the cardioversion. The last 35 consecutive patients undergoing DCCV for AF before the new protocol was introduced were compared with the first 35 patients having DCCV under the new protocol.
The time to perform 35 consecutive cardioversions was reduced from 32 months to 10 months. The new system resulted in no cancellations for administrative reasons and only one patient for a clinical reason. Sinus rhythm (SR) was restored in 60% cases under the new protocol (double the success rate before the new protocol) and 76% patients discharged in SR under the new protocol, remained in SR at clinic follow-up.
A simple change in the method of delivering a clinical service has resulted in an improvement in both the administration and clinical outcome for patients. Such changes, requiring co-operation between anaesthetic and cardiology departments, could be implemented widely for the benefit of many patients.
Chronic atrial fibrillation (AF) is a common condition and its prevalence increases with age, affecting up to one in 10 people over the age of 75. Treatment strategies include either control of the ventricular rate (rate control) or restoration of sinus rhythm (SR) (rhythm control). It is argued that restoration of SR is preferred over rate control. Benefits include symptom improvement and increased exercise tolerance, as well as a reduction in thromboembolic risk. In addition, it avoids the added complications of long-term anti-arrhythmic therapy and anticoagulation in patients who remain in AF.
Direct current cardioversion (DCCV) involves a general anaesthetic, during which a synchronised DC counter shock is applied to the heart through defibrillator pads placed on the patient's chest in the same position as for emergency defibrillation. The shock is synchronised to discharge on the R wave of the QRS complex on the electrocardiogram (ECG), and so avoids conversion of the rhythm to ventricular fibrillation. If the first shock of 50J fails to restore SR on the ECG, the energy is increased in increments until 360J.
DCCV is a cost-effective approach to the management of AF, although AF frequently recurs within the first year of a successful DCCV. In such circumstances patients may require further cardioversion and/or anti-arrhythmic therapy to restore and maintain SR, or long-term anti-arrhythmic therapy for rate control if AF persists. The likely success of DCCV depends on the duration of AF: longer duration makes the restoration of SR less likely, as does the presence of a structural abnormality within the heart, such as rheumatic valve disease, left ventricular dysfunction and an enlarged left atrium. DCCV is not without risk. It is associated with a risk of thrombo-embolism and, more rarely, prolonged asystole or bradycardia.
This paper describes what we believe to be an innovative approach to the organisation of elective cardioversion of AF patients within a 650-bed district general hospital.
The timing and effectiveness of a new protocol for organising direct current cardioversion (DCCV) for patients with atrial fibrillation (AF) was compared with the existing system in a medium-sized district general hospital in the United Kingdom. The new protocol comprised a monthly dedicated DCCV list in the operating theatres, with an anaesthetist and an Operating Department Assistant providing anaesthesia, and cardiology medical staff performing the cardioversion. The last 35 consecutive patients undergoing DCCV for AF before the new protocol was introduced were compared with the first 35 patients having DCCV under the new protocol.
The time to perform 35 consecutive cardioversions was reduced from 32 months to 10 months. The new system resulted in no cancellations for administrative reasons and only one patient for a clinical reason. Sinus rhythm (SR) was restored in 60% cases under the new protocol (double the success rate before the new protocol) and 76% patients discharged in SR under the new protocol, remained in SR at clinic follow-up.
A simple change in the method of delivering a clinical service has resulted in an improvement in both the administration and clinical outcome for patients. Such changes, requiring co-operation between anaesthetic and cardiology departments, could be implemented widely for the benefit of many patients.
Chronic atrial fibrillation (AF) is a common condition and its prevalence increases with age, affecting up to one in 10 people over the age of 75. Treatment strategies include either control of the ventricular rate (rate control) or restoration of sinus rhythm (SR) (rhythm control). It is argued that restoration of SR is preferred over rate control. Benefits include symptom improvement and increased exercise tolerance, as well as a reduction in thromboembolic risk. In addition, it avoids the added complications of long-term anti-arrhythmic therapy and anticoagulation in patients who remain in AF.
Direct current cardioversion (DCCV) involves a general anaesthetic, during which a synchronised DC counter shock is applied to the heart through defibrillator pads placed on the patient's chest in the same position as for emergency defibrillation. The shock is synchronised to discharge on the R wave of the QRS complex on the electrocardiogram (ECG), and so avoids conversion of the rhythm to ventricular fibrillation. If the first shock of 50J fails to restore SR on the ECG, the energy is increased in increments until 360J.
DCCV is a cost-effective approach to the management of AF, although AF frequently recurs within the first year of a successful DCCV. In such circumstances patients may require further cardioversion and/or anti-arrhythmic therapy to restore and maintain SR, or long-term anti-arrhythmic therapy for rate control if AF persists. The likely success of DCCV depends on the duration of AF: longer duration makes the restoration of SR less likely, as does the presence of a structural abnormality within the heart, such as rheumatic valve disease, left ventricular dysfunction and an enlarged left atrium. DCCV is not without risk. It is associated with a risk of thrombo-embolism and, more rarely, prolonged asystole or bradycardia.
This paper describes what we believe to be an innovative approach to the organisation of elective cardioversion of AF patients within a 650-bed district general hospital.