Heart Failure

Introduction:

Heart Failure (HF) continues to be a major heart problem and an important cause of hospitalization in India. The number of patients with HF has been gradually increasing due to improving life span of patients and improved survival after heart attacks in the last few years. More patients are being saved from heart attacks due to better availability of drugs and immediate revascularization of the blocked vessels. Though this is heartening news, the number of patients with poor heart function has been increasing all over the country.

What is Heart Failure?

Heart Failure does not mean that heart has stopped working or is about to stop working. HF is a condition in which the heart becomes so weak that it has trouble pumping a normal amount of blood carrying enough oxygen and nutrients to meet the body’s needs.

 

What causes HF?

HF develops either as a result of (1) damage to the heart muscle (which could be caused by coronary artery disease,  infection or toxic exposure to chemicals such as alcohol and drugs) or (2) when too much strain is placed on the heart because of years of untreated high blood pressure or an abnormal heart valve.

 

What is the commonest cause of Heart Failure/ heart muscle damage?

The commonest cause of HF is coronary artery disease where in the blockages of the coronary arteries cause damage to the heart muscle thereby reducing the pumping of the heart. The loss of pumping function of the heart is directly related to how fast the patient seeks treatment for a heart attack. Patients who receive treatment within one hour of onset of chest pain due to a heart attack do well as the heart muscle is salvaged from further damage due to early intervention in the form of drug treatment or angioplasty. Damage to the heart muscle due to drugs, alcohol or infections is the second common cause of HF.

 

What do the patients complain of?

The commonest symptom is shortness of breath, also called dyspnea, which is caused by accumulation of fluid in the lungs due to failure of the left side of the heart.

Swelling of feet, ankles, legs and abdomen due to accumulation of fluid is caused by failure of the right side of the heart.

Chronic cough, loss of appetite and fatigue are some of the symptoms which patients experience.

Some of the patients may complain of palpitations which may be caused by irregular heart beats.

 

Diagnosis of HF:

Patients are mostly diagnosed by their physicians due to their typical symptoms and then advised to undergo tests like Electrocardiogram, Echocardiography and Coronary angiography.

  1. The Electrocardiogram (ECG) give information about the rhythm of the heart, any electrical disturbance of the heart and also if the blood supply is less.
  2. The Echocardiography is the sonography of the heart wherein its imaged and the pumping of the heart is studied. It’s the most important test to diagnose heart failure. It gives the physician information on heart pumping, the function of the valves and leaks across the valves. The pumping of the heart can be quantified as Ejection Fraction (EF) which is normally in the range of 55-65%. Any decrease in EF below the normal range suggests some weakness of the heart muscle and needs to be investigated further. Patients with EF lower that 35% entail more risk of sudden death and heart failure hospitalizations and need more specialized treatment.
  3. Coronary angiography: is necessary to diagnose blockages in the coronary arteries which would need subsequent correction by either angioplasty or bypass surgery.

 

Risks of Heart Failure:

Patients with HF are at high risk of Sudden Cardiac Death and recurrent hospitalizations due to heart failure episodes. The patients at most risk are the ones with an EF of less than or equal of 35%. HF patients keep getting admitted in hospitals due to recurrent dyspnea which need to be treated with intravenous medications.

 

Devices in Heart Failure:

There are 2 devices which can be used in HF treatments (1) Cardiac Resynchronization Therapy and (2) Implantable Cardiac Defibrillator

 

 

Summary:

Patients with heart failure are at risk of dying from progressive heart failure and sudden cardiac arrest. This can be now corrected and treated effectively by implanting devices (namely CRT and ICD respectively). However, these patients need to be carefully evaluated and selected by the cardiologist before undergoing these procedures so as to ensure maximum benefit.

 

 

Sudden Cardiac Arrest

Image Courtesy: Heart Rhythm Society

October is SCA Awareness Month!

Assess Your Risk of SCA (Sudden cardiac arrest) with the Heart Rhythm Society’s online quiz 

What is the difference between Sudden Cardiac Arrest (SCA) and Heart Attack?

ANS:  Heart attack damages the heart while SCA stops the heart.

Heart attack is caused by blockages in the blood supply (coronary arteries) of the heart. The patient complains of acute severe chest pain at rest. In some patients, it may be associated with vomiting, fatigue, breathlessness, sweating and also pain in the arms.

Sudden Cardiac Arrest is caused by sudden electrical disturbance of the heart. This is mostly caused by ventricular tachyarrhythmias, (wherein the lower chambers of the heart beat so fast that there is no effective output of blood from the heart) or by cardiac standstill (no effective heart rhythm). This causes loss of consciousness with brain death ensuing in the next 4 minutes, causing eventual death.

         Who is at risk of SCA?

ANS: Patients with prior heart attacks are the most at risk of SCA. 80-85% of the patients who have SCA have coronary artery disease. Majority of the patients have poor heart pumping function which is called as ejection fraction. The ejection fraction of the heart gives an idea about the output of the heart. Normally ejection fraction is in the range of 55 to 70%, however, patients with most risk of SCA have ejection fraction less than 35%.

Other patients who are more at risk of developing SCA are patients with dilated hearts and electrical disturbances of the heart.

         How to respond to SCA?

ANS:  Death can ensue within minutes of SCA and so prompt CPR (cardiopulmonary resuscitation) is absolutely necessary. Along with it, the patients needs to be electrically shocked (defibrillated) with the help of AED (Automatic External Defibrillator). AED are installed in most of the public utility buildings in most of the western countries and also available with all the ambulance services. The AED promptly detects the abnormal rhythm of the heart and can shock the patient out of it. However, in India, due to the dearth of trained ambulance personel, lack of AED in public places and also not much of awareness about CPR, the outlook for these patients is dismal. Only 5% of the patients are revived successfully and taken to the hospital. A practical step would be to call a doctor or an ambulance immediately.

         How to prevent SCA?

ANS: Patients with prior heart attacks are the most prone for SCA. Though the patient may have undergone angioplasty or bypass grafting to restore the blood supply to their hearts, they are still at risk if the ejection fraction is less than 35%. These patients need to be evaluated by a Cardiologist, preferably a Cardiac Electrophysiologist, to ascertain their risk to develop SCA. Patients with history of prior syncope (loss of consciousness) and history of early deaths due to SCA may need thorough testing.

The basic investigation required is the 2D-echocardiography to ascertain one’s ejection fraction. Patients with low ejection fraction need to be started on medications to reduce their risks of SCA. Some patients need an electrophysiology study (EP study) to study their risk of develop SCA. EP study is a simple procedure in which 3 to 4 wires are placed in the heart via the groin to study the susceptibility to develop SCA. ICDs (implantable cardiac cardioverter defibrillators) are implanted in patients with high risk of SCA. ICDs are small devices which are implanted in the chest. These devices monitor one’s heart rhythm all the time and deliver a small shock in case the dangerous rhythm develops. ICDs are life saving devices, but cost around 4 to 8 lacs depending on the type of device used. They are proven to treat these dangerous rhythms successfully and reduce chances of dying due to SCA by 25 to 35%. There are also non-invasive electrocardiography investigations like 24 hours ECG recording, Treadmill test and ECGs with special markers to detect T-wave alternans, Heart rate variability and Late potentials. All of these investigations are now available at Hinduja Hospital.