News

The statistics are staggering. Five million people in the United States suffer from heart failure. And, it’s the only major cardiovascular disorder that’s increasing in incidence, with 400,000 – 700,000 new cases diagnosed every year.

Poor blood flow caused by a weakened heart muscle is called congestive heart failure. For some congestive heart failure patients, another problem in the heart’s electrical system can make the walls of the heart’s main pumping chamber squeeze in the wrong sequence. This worsens the heart’s already limited ability to move blood. This electrical (or conduction) defect can make matters much worse.

Patients experience fatigue, shortness of breath, difficulty breathing while lying down, confusion, and swelling in their legs, feet, and ankles. The unsynchronized beating of the heart decreases the amount of blood flow out into the body, further damaging the heart as well as other vital organs. Those who suffer from heart failure (New York State Heart Association Class III and IV patients) often experience significant limitations in their activity and it greatly affects their quality of life.

The Hudson Valley Heart Center’s Congestive Heart Failure Program has added a promising new treatment to their arsenal that is being hailed as the first major breakthrough since the development of specialized heart failure drugs - bi-ventricular pacing. For many patients, it has meant the difference between living a normal life and being bedridden.

“Soon after receiving a bi-ventricular pacing device, patients experience an increased capacity for physical activity that allows them to resume many of their daily activities”, adds The Heart Center’s Dr. Sankar Varanasi, who has specialty training in arrhythmia management and pacing.

Bi-ventricular pacing has given The Heart Center new ammunition in the fight against heart disease. It’s one more step they can offer to aggressively minimize the debilitating symptoms of heart failure. The Heart Center, with several practice locations in the Hudson Valley, is the only practice between Albany and Westchester to offer bi-ventricular pacing.

How bi-ventricular pacing works
Since its recent inception, numerous types of bi-ventricular pacers have been introduced that dramatically improve arrhythmias and/or synchronization problems.

A bi-ventricular pacemaker is similar to a traditional pacemaker with an additional lead. The tip of one lead is placed in the right ventricle while the tip of the other lead is placed just outside the left ventricle in a vein along the lateral wall. The device is able to monitor and deliver impulses to either or both chambers of the heart, helping them contract in rhythm again. Another device, the bi-ventricular defibrillator is implanted in the same way, but the right ventricle lead has the additional ability to shock the heart back to a normal pace. This is especially beneficial to patients who have experienced a heart attack and are at risk for Sudden Cardiac Death, which claims 300,000 to 400,000 lives each year.

These devices are slightly larger than a traditional pacemaker, and are implanted below the collarbone in about an hour and a half using local anesthesia. Patients are often sent home within a day or two.

Who can benefit from bi-ventricular pacing

Candidates for a bi-ventricular pacemaker include those patients with:

• Class III or IV heart failure, as classified by the New York Heart Association
• an ejection fraction of 35 percent or less
• a QRS Complex on a surface EKG of greater than 130 milliseconds

Candidates for a bi-ventricular defibrillator include those patients with:

• a prior heart attack
• an ejection fraction of less than 40 percent
• any non-sustained VT (triplets count)
• a positive EP study

Recent trials
Two recent trials on cardiac resynchronization using bi-ventricular pacing produced positive reports, suggesting that cardiac resynchronization therapy does result in functional improvement for a statistically significant number of advanced heart failure patients. The MUSTIC Study and the MIRACLE Trial both evaluated therapy involving new implantable bi-ventricular systems that synchronize the beating action of the left and right heart chambers in patients.

The MUSTIC Study

This controlled randomized crossover study, compared New York Heart Association Class III patients’ exercise tolerance and quality of life when their implanted systems were activated compared with those indicators during a time when their systems were turned off.

Cardiac resynchronization systems were implanted in 58 heart failure patients. Half of this group immediately had their systems activated for 12 weeks while the other half’s systems were not activated for 12 weeks. Then the groups “crossed over”. Those with activated systems had theirs turned off for 12 weeks, while the other half had theirs turned on.

The study showed that during the time patients had their systems activated, they could walk 23% farther than when their systems were not activated. When asked to compare their quality of life with and without activation of the implanted systems, the patients’ scores indicated a 32% improvement when their heart action was optimized with the therapy.

The MIRACLE Trial

This trial was set up to evaluate the safety and effectiveness of the Medtronic InSync cardiac resynchronization system. 266 New York State Heart Association Class III or IV heart failure patients were randomly assigned to either a control group or a resynchronization therapy group. All received the implant; the control group did not have their devices activated during the study.

Results stemming from the completion of the study indicated that 69% of patients who received resynchronization therapy had an increase of at least one NYHA heart failure class, while 34% experienced this improvement in the control group. An improvement in one class significantly improved patient vitality, and they were able to perform for longer periods on standard exercise testing. After six months, patients who were in the control group universally wanted their devices turned on.

All of the patients in both the MUSTIC Study and the MIRACLE Trial were maintained on medical therapy as well.

Diagnosis and the initiation of treatment

Heart failure is a common and serious disease that needs to be diagnosed and treated as early as possible. Primary care physicians and internists play an important role in identifying those patients who are at risk or who already show signs of congestive heart failure.

The Hudson Valley Heart Center’s Congestive Heart Failure Program offers a multi-disciplinary approach that treats the whole patient. Patients benefit greatly from a proactive team that includes their doctor, nurse practitioners, an exercise physiologist, dieticians, and access to support groups and clinical research trials.

Current and ongoing studies have yet to reveal the long-term prognosis of patients who are receiving cardiac resynchronization therapy. But study results thus far should bring hope to thousands of patients whose quality of life has been severely affected by congestive heart failure.