Causes and Symptoms of Congestive Heart Failure

In the United States, more than three million people are living with heart failure (HF), and more than 400,000 new HF patients are diagnosed each year. Coronary artery disease, a partial blockage of the blood vessels in the heart muscle, causes most cases of HF. Ischemic heart attack, a complete blockage of blood supply to a part of the heart muscle, destroys tissue and impairs the heart's ability to provide sufficient blood flow to the body.

Other contributing factors to HF include: cigarette smoking, high blood pressure (hypertension), obesity, diabetes, Alcohol abuse, HIV infection, and the effects of certain chemotherapeutic agents used to treat cancer.

Ventricular partitioning is performed in the cardiac catheterization suite and uses a similar approach to common left-heart percutaneous procedures. A device, the “The PARACHUTE^TM Implant,” is introduced through the femoral artery to the left ventricle through a flexible catheter. Once properly positioned in the bottom, or apex of the left-ventricle, the The PARACHUTE^TM is opened. The device is affixed to the ventricle wall with very thin nitinol struts to form a partition. The catheter is then removed and the femoral artery access site is closed.

HF describes a wide array of symptoms, and varying levels of severity. HF is classified according to the side of the heart involved, right or left ventricle, and whether the abnormality is related to the heart's inability to pump, or a high pressure in the vascular system that requires abnormally high cardiac output. Class III patients are unable to perform most normal daily activities, and are comfortable (not out of breath), only when at rest. Class IV patients are unable to perform any activity, and have symptoms even when at rest.

HF patients with left-sided failure have left ventricle abnormalities that are most frequently caused by previous ischemic heart attack, and present with symptoms including fatigue, and extreme breathlessness with exertion (dyspnea). Some patients experience an increase in breathlessness when lying down (orthopnea), and are most comfortable sleeping with pillows, in a semi-sitting position. Patients may also have sudden attacks of severe breathlessness during sleep (paroxysmal nocturnal dyspnea), similar to an asthma attack.

Right-sided HF patients commonly have excess fluid accumulation build up in the body, causing swelling under the skin that affects lower extremities. Frequent night time urination is common as fluids are returned to the bloodstream during sleep. In severe cases swelling may affect the liver and cause jaundice (a yellow hue to the skin).

The PARACHUTE^TM Procedure

The PARACHUTE^TM procedure intends to address heart failure patients who have developed left-sided heart failure following a Myocardial Infarction (MI) heart attack. MI typically damages the heart muscle, due to lack of blood supply to the region during heart attack.

After MI many HF patients experience enlargement of their left ventricle causing a decrease in cardiac output resulting in heart failure symptoms such as shortness of breath. The PARACHUTE^TM partitions the damaged muscle, isolating the non-functional muscle segment from the functional segment, and decreases the overall volume.

CardioKinetix, Inc. has developed a percutaneous treatment for patients with left ventricular dilation after an anterior MI. The implantable device, called the PARACHUTE^TM is a partitioning membrane deployed within the compromised ventricle. The PARACHUTE^TM isolates the dysfunctional region of the ventricle and decreases chamber volume, thereby increasing cardiac output. Options for patients whose ventricle has enlarged are limited, with most on medical therapy and/or a cardiac resynchronization device that only benefits heart failure patients with a specific EKG pattern.

The PARACHUTE^TM procedure is performed in the cardiac catheterization lab or surgical suite, with the patient receiving local anesthesia . Under imaging guidance, the physician inserts the self-attaching PARACHUTE^TM device through the femoral artery, and deploys it into the apex of the left ventricle. The PARACHUTE^TM device partitions off the portion of the ventricle affected by the damaged myocardium, reducing the volume of the ventricle by approximately 20%, and reshapes the ventricle to a more natural conical shape. The reduced volume reduces wall stress and increases contractility and ejection fraction (a measure of the effectiveness of the ventricle).

The PARACHUTE^TM device, implanted by an Interventional Cardiologist, has demonstrated in feasibility trials that patients experience a significant decrease in heart failure symptoms and an increase in exercise capacity and quality of life; with virtually no device related safety events. The feasibility trial also established that the device can be implanted with ease by interventional cardiologists under local anesthesia, with patients discharged in twenty-four hours.

Diagnosing Congestive Heart Failure

Heart Failure (HF), describes a wide range of clinical problems that reduce the heart's ability to supply adequate blood flow to the body. Some physicians are more comfortable describing HF as a syndrome, comprised of a variety of symptoms that must be treated together.

Physicians use a variety of tests to confirm congestive heart failure (CHF). Diagnostic testing is recommended in the presence of symptoms, including: shortness of breath, fatigue, swelling in the feet or ankles, and increased heart or breathing rate.

Patients are often first evaluated using a chest X-ray; the physician looks for an enlarged heart, or fluid in the lungs. In patients who have previous history of ischemic heart attack, angiography may be used to look for any new blockages in the coronary arteries. Patients may also receive an electrocardiogram (EKG), a quick painless test that measures electrical activity in the heart. The physician will read the EKG tracing to look for abnormal rhythms or out-of-sync heart beats.

One of the most common measurements used to confirm CHF is the Ejection Fraction (EF), which measures the hearts ability to pump blood through the body. A mathematic equation compares the volume of blood in the left ventricle, before and after the heart beats in each cardiac cycle, and expresses the percentage of total ventricle volume 'ejected' from the heart with each beat. EF is represented as a percentage - a healthy male in the United States, weighing 154 pounds, will have an EF of 58%. A typical CHF patient may have an ejection fraction of 35% or less.

Ejection fraction may be measured using an Echocardiogram, a non-invasive ultrasound procedure that measures the size of the heart's chambers in real time. Physicians use precise measurement of ventricles during the heart beat to determine the precise volume of blood flow. Doppler ultrasound imaging allows physicians to visualize, in real time, the flow of blood entering and leaving the ventricles in the heart.

CHF patients are classified, based upon their symptoms and the resulting limitations on their activities. Class 1 patients have no symptoms (although there is an underlying finding of heart failure). Class II patients have mild symptoms, some limitations on normal activity, but are comfortable at rest. Class III patients are very limited in their activities, and are only comfortable at rest. Class IV patients experience severe limitation of activity, and have symptoms even while at rest.

Treating Congestive Heart Failure

Most patients living with heart disease respond to treatments that help reduce fatigue, shortness of breath, and other symptoms. Medical professionals often use a multidisciplinary approach to CHF patients that includes treatment, rehabilitation, and lifestyle counseling. Patients may be asked to work with a dietician, physical therapist, cardiologist, and other specialists.

Clinical treatment for CHF often begins with drug therapy. Several clinical studies suggest that the most common reason that medications don't improve symptoms is that patients fail to follow prescribed doses and dosing schedules. Keeping track of all medications, and avoiding dangerous drug interactions is a key to benefitting from CHF treatment.

Prescription medications commonly used to treat CHF include:

• Vasodilators - also known as ACE Inhibitors, are often the first choice in treatment. This class of drugs has been proven clinically to slow the progression of heart disease. The drugs act on the blood vessels, causing them to expand, which lowers blood pressure and reduces the amount of work the heart must do to maintain blood flow to the body.
• Diuretics - also known as 'water pills,' help the body to remove excess fluid from the bloodstream. The drugs act on the kidneys, and helps them to convert more water and sodium in the blood to urine. As there is less fluid in the bloodstream to pump, the workload on the heart is reduced.
• Digitalis Preparations - are used to increase the force of contractions with each beat of the heart. The drugs act directly on the heart muscle tissue, and the stronger contractions force more blood flow through the heart, which reduces CHF symptoms.
• Beta Blockers - help the stressed heart to slow down it's rhythm. The receptors in muscle tissue cells are dulled, lowering heart rate and blood pressure, which improves symptoms.

Medical devices are used to treat CHF, either to 'assist' with ventricle pumping, or as 'resynchronization' aids to ensure the heart beats as efficiently as possible. The Left Ventricular Assist Device (LVAD) is a mechanical pump-type device that helps the heart muscle to maintain adequate blood flow to the body. The device is often used as a "bridge to transplant" solution; implanted in the body, the LVAD is attached to the heart, sending blood to the aorta, bypassing the weakened ventricle.

Implantable defibrillators are used to deliver an electric shock to the heart when an irregular heart rhythm is detected by the device. A Cardiac Resynchronization Therapy (CRT) device emits a countershock that is delivered during a life-threatening abnormal rhythm, restoring the proper pacing to the heart beat.

Surgical intervention is also used to treat CHF, including procedures to repair damaged portions of the heart, up to and including heart transplant. Patients for whom ischemic heart attack is the cause of CHF, may need coronary artery bypass surgery, to restore blood flow to a damaged portion of the heart muscle. Angioplasty may be used to open clogged blood vessels in the heart as a means of restoring blood supply to the heart.

Living With the Symptoms of CHF

Before his heart attack, Dean Tackett was in charge of a very busy radiology department at a community hospital in central Ohio. Dean's days started early, and often lasted well beyond the traditional nine to five. "I was always someone used to a busy, active life," he said. "I worked for forty-one years in the medical field, and I knew that after my serious heart attack, my options were limited."

The greatest thing about it was that I could do more. Being retired, I was in no hurry to do anything, but I could do a lot more. I could do things. I could walk further. I could do and accomplish more at one time without having to sit down and rest.

- Dean Tackett

Dean had the Parachute procedure when medication and other therapy did not relieve his extreme fatigue. "When I got up in the morning I needed to lie down to rest after something as simple as shaving, brushing my teeth, or eating breakfast,' Dean recalled. After the Parachute procedure he noticed a difference within a few weeks, "Now, when I wake up in the morning, I can shower and shave and eat breakfast without stopping to rest in between."

Dr. Ernest L. Mazzaferri Jr., Dean's physican, noted, " The majority of these patients have congestive heart failure symptoms from a history of a prior heart attack on the front side of their heart, and they have very intense limitations of their lifestyle." Dr. Mazzaferi explained to Dean that the bottom part of his heart was no longer pumping, and implanting the Parachute device would reshape this area of his heart, effectively excluding the damaged portion.

All of the patients treated by Dr. Mazzaferri with the Parachute device left the hospital the following day. He recalled Dean's procedure very vividly, "Dean Tackett’s wife probably gave us the most interesting insight right after the procedure, as he wheeled into the room. She welled up with tears in her eyes, and said she hasn’t seen that kind of color in Dean in a long time."

Dean Tackett experienced a significant change after the procedure, "The greatest thing about it was that I could do more. Being retired, I was in no hurry to do anything, but I could do a lot more. I could do things. I could walk further. I could do and accomplish more at one time without having to sit down and rest."