DC or direct current cardioversion is a therapeutic procedure used to treat abnormal heartbeats. The medical term for abnormal beats is cardiac arrhythmia. An arrhythmia can be a fast or slow heart rhythm. Cardioversion treatment uses electricity to recalibrate your heart. While researchers have identified ways to make it more successful, if you suffer from certain conditions the success rate is lower.
A factor you cannot control that affects success of cardioversion is the size of your left atrium or heart chamber. According to a study published in Experimental & Clinical Cardiology, individuals with a smaller left atrium as measured on transthoracic and transesophageal echocardiography had a better success rate of conversion to sinus rhythm both following cardioversion and at their one-year post procedure follow-up visit.
The type of cardiac disease you have also affects the success rate of cardioversion. Initially, DC cardioversion is successful in approximately 94 percent of patients. Unfortunately, only 40 to 60 percent of patients have maintained normal sinus rhythm at their three-month follow-up visits. The Department of Internal Medicine and Hypertension at the University of Medicine at Warsaw in Poland says the success of the procedure depends on the individuals underlying cardiac disease and the type of anti-arrhythmic treatment utilized. Despite best treatment efforts, at four-year follow ups only 30 percent of the patients studied maintained normal sinus rhythm.
The way in which the procedure is performed also affects the success rate. External factors include correct placement of the paddles during treatment. Guidelines from the International Liaison Committee on Resuscitation suggest specific paddle placement to deliver adequate current to the chest wall. In addition to placement, paddle size is an important factor in successful treatment, according to an article published in "The Annals of Saudi Medicine." Other external factors that impact success rate include the size of the electrodes used.
Atrial fibrillation or AF is the arrhythmia most often treated with direct current cardioversion. The procedure works well for most individuals, but if you have a condition known as persistent atrial fibrillation it is less likely to be successful. In this condition, your heart generates an abnormal electric current even though you have been treated. An article published in "Clinical Cardiology" studied the use of a medication called sotalol which was given to 53 patients with refractory persistent AF. After taking the medication, the patients underwent repeat DC cardioversion. The authors found the medication improved the success rate of treatment. This resulted in normal heart rhythms in 67 percent of the patients upon follow up.
- "Cardiology" DC Cardioversion of Persistent Atrial Fibrillation: A Comparison of Two Protocols
- "Clinical Cardiology": Rate of Conversion and Recurrence After Sotalol Treatment in Patients With Direct Current Refractory Atrial Fibrillation; A Nergardh, et al, 2/29/2006
- "Experimental & Clinical Cardiology"; Factors Related to the Early and Late Success of Direct Current Cardioversion of Chronic Nonrheumatic Atril figrillation; Marcin Szulic, MD, 2001
- "Annals of Saudi Medicine"l Electrical Cardioversion; Murat sucu, et al, 2009