The normal heart
The heart has the vital responsibility of throughout the body pumping blood. It delivers oxygen and nutrients to the cells and takes waste materials for disposal.
The heart consists of two pairs of chambers; the atria and the ventricles. These chambers are connected in a series by valves to form the right and left sides of the heart. The right heart pumps blood into the lungs while the left delivers to the rest of the body.
The pumping function of the heart is divided into two parts and explained with the heartbeat. It is mainly; diastole- the resting phase in between the beats where the heart chambers fill up with blood-, and systole– the contracting phase that pumps the blood felt as pulse in the body.
(Read more on circulation in “Arteries Vs Veins”).
Heart failure and congestive heart failure are the terms used when the heart is unable to adequately meet the needs of the body. The problem can be either in the filling phase or in the pumping function. It results in fluid and blood building up in the lungs and in the body, thus, the term congestive heart failure (CHF).
CHF affects millions of people worldwide. It is one of the leading causes of death. The heart is ineffective in supplying oxygen and nutrients to the body according to its needs and it eventually leads to injury and death of the organs.
Heart failure is classified according to the phase involved and the affected side of the heart. So, functionally speaking, it can be:
- Systolic heart failure– the heart muscles are not contracting enough to adequately pump the blood; the heart muscles may be too thin, too stiff, or injured by oxygen and nutrient deprivation.
- Diastolic heart failure– the heart chambers are not getting filled with enough blood; either the chamber cavity size is reduced or the heart muscles are too stiff.
Then determining the side of heart failure:
- Left-sided heart failure- this type of heart failure results in the blood pooling in the lungs and thus the symptoms are mostly related to breathing. Left-sided heart failure is a common, mostly systolic failure, and leads to involve the right side.
- Right-sided heart failure– this type results in the blood getting pooled in the body. Right-sided heart failure is less common, and mostly occurs with worsening of left-sided failure; only some conditions cause isolated right-sided failures, like large septal defects.
Causes and risks:
Different conditions affect the heart differently. The usual process is that any particular condition affects one phase and one side of the heart at first, and since the heart chambers are connected in a series, it progresses to involve the whole heart. Some conditions affect the structure of the heart- wall width, cavity size, and the valves- while others disturb the functionality- heart muscle and the electric circuit of heart.
Some of the common conditions are:
- Ischemic heart disease/Coronary artery disease
- Valvular heart diseases
- High blood pressure or hypertension
- Cardiac muscle diseases
- Septal defects
- Lung diseases
- Thyroid issues
- Alcohol abuse
- Rhythmic irregularities
- Some Viral infections
- Medicines like painkillers, anti-diabetics
Some identified risk factors that contribute to causes of heart failure and, in turn considered risk factors for heart failure, include:
- poorly controlled blood pressures
- high lipids
- uncontrolled sugars
- family history
- heart valve disease
- alcohol and drug abuse
- connective tissue disorders, such as SLE,
- older age
In cases of left heart failure, the blood starts pooling in the lungs. Raised pressure in the lungs results in congestion and fluid leakage into the lung tissues. This slows the process of oxygenation and the patient may present with difficulty breathing; with activity, with rest, and while lying down. There may also be cough and crackling sounds from the chest on breathing. Conversely, right-sided failure results in fluid building up in the whole body. It leaks from the vessels into organs and tissues, causing swelling and damage to the organ. The most fluid gets pulled to the feet and ankle due to gravity and presents as pedal edema. Other symptoms include fatigue, chest pain, dizziness, irregular heart beat, aches, nausea, bloating, abdominal distension with ascites.
Some cases develop progressively and present with symptoms slowly over time, while some patients can develop overt failure and present as heart attacks and fluid overload in lungs.
According to the New York Health Association, there are four functional classes of heart failure:
- Class I: No limitation of physical activity
- Class II: Slight limitation of activity, comfortable at rest
- Class III: Marked limitation of activity, comfortable at rest
- Class IV:Severe limitation of activity, symptomatic at rest
Diagnostic Tests and procedures:
Some common tests done to evaluate the condition of the heart include
- Electrocardiogram (EKG, ECG) to check heart rhythm and indirectly check for heart size
- Echocardiography-assesses the walls, chambers, valves, the phases of heart pumping, and the ejection fraction
- Chest X-ray-gives the size of heart and fluid in lungs
- Blood tests to look for organ damage
- The B-type natriuretic peptide is a chemical released from the heart when in failure.
- Other tests that are done include thallium scans, angiography, stress echo, etc.
The main goal is to improve the pumping of the heart and treat the underlying cause.
Lifestyles modifications significantly prevent heart failure from happening and worsening. Such factors include:
- well-balanced, low salt diet,
- ideal weight maintenance,
- regular exercise,
- no smoking,
- better control of blood pressure, sugar and cholesterol,
- and fluid restriction.
Medications to restrict and reduce the fluid level are given, such as ACE inhibitors, ARBs, diuretics, and spironolactone. The heart rhythm and rate are controlled for efficient filling and pumping by Beta-blockers and digoxin. Ventricular assist devices and heart transplants are options for end-stage or class IV patients.
Heart failure means impaired heart function, enough to disturb the normal body functions. It is a progressive disease and can affect the quality of life. However, with a modified and healthier lifestyle, and proper management of medications, many patients lead near-normal lives.