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Cardioversion turns 50

Seth Bilazarian MD

Private practice

theheart.org

• 50 years ago today, Lown et al described cardioversion as a "new electronic method"

http://www.nejm.org/doi/full/10.1056/NEJM196308152690701

"A new electronic method"

• Atrial fibrillation:• Is the most prevalent of the chronic rhythm

disorders of the heart• Increased tendency to systemic and pulmonary

emboli• Impairs cardiac performance

• New method was designated "cardioversion"

http://www.nejm.org/doi/full/10.1056/NEJM196308152690701

A lot hasn't changed

• The method of terminating AF has not changed since Frey introduced quinidine in 1918

• Quinidine commonly produces untoward reactions that range from gastrointestinal upset to sudden death. The American literature alone has documented 26 deaths up to 1956

http://www.nejm.org/doi/full/10.1056/NEJM196308152690701

Some things have changed

• Single limitation is the need for anesthesia. Patient is usually unconscious for 2-5 minutes, procedure completed in 15-30 minutes.

• Cardioversion is safe:• When DC pulse is synchronized to discharge outside the ventricular

vulnerable period, the possibility of fibrillation is entirely prevented• EKG before and after reversion showed no change in the ventricular complex.• In a few patients persistent sinus bradycardia, episodic nodal rhythm and

atrioventricular dissociation occurred. These either were the result of overdigitalization or perhaps represented depression or pre-existing injury of the sinus node.

• Definite but small risk of embolism with any reversion of AF to normal rhythm. Therapy is carried out for a period of 3 weeks before and 1 week after cardioversion.

What else hasn't changed?

http://www.nejm.org/doi/full/10.1056/NEJM196308152690701

"This procedure has been designated as cardioversion, and the instrument is referred to as a cardioverter."

One name caught on, one didn't

http://www.nejm.org/doi/full/10.1056/NEJM196308152690701

Source: 2008 to 2012 Medicare Physician Fee Schedule, national average (unadjusted) rates. 2008 to 2012 Medicare Physician Claims Database (100% sample). Created by Dr Seth Bilazarian

Medicare claims data analyses

Source: 2008 to 2012 Medicare Physician Fee Schedule, national average (unadjusted) rates. 2008 to 2012 Medicare Physician Claims Database (100% sample). Created by Dr Seth Bilazarian

Medicare claims data analyses

Source: 2008 to 2012 Medicare Physician Fee Schedule, national average (unadjusted) rates. 2008 to 2012 Medicare Physician Claims Database (100% sample). Created by Dr Seth Bilazarian

Medicare claims data analyses

2008 2009 2010 2011 20120

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Cardioversion

Cardioversion

year

Decline in our use of cardioversion

Source: Dr Seth Bilazarian

Contributing to the numbers

Growing because:• AF increasing with aging population and increase in obesity• Ease of TEE and cardioversion• "Part" of the AF ablation treatment algorithm

Not growing as fast:• Comfort with rate control alone in asymptomatic patients• Use of ibutilide (Corvert) as an alternative

Management of AF with the rhythm-control strategy offers:• No survival advantage over the rate-control

strategy• Potential advantages, such as a lower risk of

adverse drug effects• Anticoagulation should be continued in this group

of high-risk patients

AFFIRM Trial 12/15/2002

http://www.nejm.org/doi/full/10.1056/NEJMoa021328

Rate control: • Safe, negative chronotropic drugs, anticoagulation• Symptoms?• AV nodal ablation and pacing

Rhythm control:• Drugs• Cardioversion• Drugs then cardioversion• AF ablation

Options for the AF Patient

• Procedure lasts 90 minutes to four hours• 30% to 40% chance it will need to be repeated• Works about 80% of the time for three to five

years but higher likelihood of recurrence beyond five years

• Procedure-related risks• Will not change the need for anticoagulation• This is not curative, it's palliative

AF ablation: Pre–EP-consult consent

• Effective nontoxic drug therapy for maintenance of sinus rhythm. We have:• Effective and toxic• Ineffective and safe• Ineffective and toxic

• Better definition of who will best benefit by AF ablation (predicted to be $2.4 billion in 2021) and improvement in acute success and durability

Still unmet need