Heart Failure Imaging - Types, Causes, Symptoms, and Techniques

Introduction

The heart's pumping activity is essential for the body to supply the cells with blood that is enriched in nutrients and oxygen. The body functions optimally when oxygen and nutrients are delivered efficiently. Heart failure is a medical term used to describe a condition wherein the heart does not pump as efficiently as it should. As a result, people experience coughs, shortness of breath, and exhaustion. Daily chores such as carrying groceries, walking, and climbing can become exceedingly tedious. It is a critical medical condition; the prognosis depends significantly on preventive measures such as lifestyle modification.

What Is Heart Failure?

A chronic, progressive disease, heart failure, refers to the inability of the heart muscle to pump adequate blood to meet the body's needs for blood and oxygen. In essence, the heart malfunctions because it is overwhelmed by its workload. The heart initially tries to compensate for this by expanding. The heart grows to contract more forcefully to keep up with the need to pump more blood. As a result, the heart enlarges over time. When the heart swells, the heart's cells also increase in size, thereby eventually resulting in the formation of additional heart muscle mass. This increased muscle mass initially enables the heart to contract more forcefully. Finally, the heart beats more swiftly to meet the body's demands.

Additionally, the body makes various efforts to compensate for the heart's diminished strength. The blood vessels become narrow to maintain and regulate the blood pressure. Further, the body diverts blood flow from less important organs and tissues. All these compensatory mechanisms are only temporary and not the primary cure or solution for heart failure. Eventually, over some time, the compensatory mechanisms fail to keep up with the demand of the body, the condition worsens, and both- the body and the heart can not keep up. Patients start experiencing symptoms, and if timely intervention is not made, the patient becomes critical. Because of these compensatory mechanisms, people do not realize that their heart is failing.

What Are the Different Types of Heart Failure?

Heart failure can be associated with the left or right side or the entire heart itself. Typically, the left side of the heart is affected first. The different types of heart failure are:

• Left-Sided Heart Failure: The heart's lower left chamber, also known as the left ventricle, is a crucial component of the cardiovascular system. Oxygen-rich blood is pumped through the aortic valve and distributed to the entire body due to the contraction of the left ventricle. Due to its significant workload, the left ventricle pumps blood at higher pressures than the other heart chambers. The left ventricle is connected with nearly all organ systems by pumping oxygen-rich blood to the body. Hence, any malfunction or disease associated with the left ventricle can be life-threatening due to its significance.

• Right-Sided Heart Failure: Left-sided heart failure frequently leads to right-sided heart failure. When the left ventricle malfunctions, increased fluid pressure is often transported back via the lungs, resulting in right-sided heart failure. When the right side of the heart malfunctions, blood starts pooling up in the blood vessels, eliciting symptoms of swollen legs, ankles, and abdomen.

What Are the Causes of Heart Failure?

Heart failure precipitates when the heart tissue gets damaged or weakens. The following conditions are associated with heart tissue damage and lead to heart failure:

• High blood pressure.

• Malfunction of the heart valves.

• Heart attack and coronary artery disease.

• Inflammatory stimulants such as infections, recreational drugs, alcohol, and tobacco, along with the toxic side effects of certain medications.

• Inflammation of the heart.

• Heart defects present since birth.

• Obesity.

• Abnormal heart rhythms.

• Other diseases, such as diabetes, thyroid disorders, etc.

What Are the Signs and Symptoms Associated With Heart Failure?

Numerous signs and symptoms are associated with heart failure, and they could be chronic or acute. They include the following:

• Shortness of breath, in general.

• Unexplained shortness of breath, especially while lying down or performing basic daily activities.

• Irregular heartbeats.

• Rapid heartbeats.

• History of persistent or chronic cough (sputum or phlegm can also be of different colors, such as pink, white, or blood-tinged, each indicating an underlying disease).

• Wheezing.

• Abdominal swelling.

• Chest pain.

• Radiating pain to the jaws, shoulder, arm, and back.

• Fluid retention in the body leads to sudden excessive weight gain.

• Swelling of the lower limbs, especially at the ankles.

• Weakness.

• Loss of consciousness.

• Fatigue.

• Mental confusion.

What Are the Various Imaging Techniques That Can Be Used to Diagnose Heart Failure?

Imaging techniques play a crucial and fundamental role in diagnosing heart failure. Various imaging techniques can be employed for the diagnosis of heart failure, such as:

• Transthoracic Echocardiography (TTE) - The most popular echocardiography, transthoracic echocardiography, is a non-invasive procedure that creates the image of the heart and its associated structures. A gel is applied to the chest, and the heart is scanned using a portable transducer. Standard transthoracic echocardiography is frequently used for screening, and occasionally, a contrast or specialized dye may be added to help amplify the scans. Although this technique has several advantages, it does not work well for individuals with decreased space between ribs, large bodies, chest deformities, or lung conditions. This is because these conditions make it difficult for the transducer to pick up signals. Additionally, intrinsic limitations of transthoracic echocardiography include its diagnostic accuracy in the case of blood clots attached to the heart walls and difficulty differentiating between myocardium (heart tissue) and blood clots. An echocardiogram helped pericardial space, right and left ventricular structure, valvular function, and anatomy.

• Cardiac Magnetic Resonance Imaging Test - Also known as cardiac MRI or CMR (cardiovascular magnetic resonance), this diagnostic technique is the gold standard test that helps visualize the heart during its normal function. This test helps medical professionals comprehend the structure and function of the various components of the heart. It also helps determine the root cause of heart failure or damage associated with a heart attack. It is the most accurate test for assessing the ejection fraction. The ejection fraction is a measure of the quantity of blood that is pumped each time the heart contracts. Cardiac MRI is a non-invasive procedure, and it captures images of the heart and its surrounding blood vessels using a strong magnet, radio waves, and a computer. A contrast dye may also be used to help amplify the images.

• Cardiac Computed Tomography (CT) scan - Also known as computerized coronary angiography, is a diagnostic imaging technique that helps visualize the blood vessels supplying the heart. Using a specialized scanner, images of the heart and its associated blood vessels are created. The characterization of left ventricular myocardial disease based on anatomy, function, and pattern is made more accessible and accurate by cardiac computed tomography. A CT scan might demonstrate the findings that can be seen on an X-ray but are more intricate and detailed. In many cases of heart failure, mediastinal lymph node enlargement is observed.

• Molecular Imaging - Molecular imaging is performed with the help of PET (positron emission tomography). Molecular imaging helps in the detailed characterization of cardiac diseases at the cellular, subcellular and molecular levels. Hence, it has the potential to assess both the severity of the heart failure and the tissue response to treatment.

• Hybrid Imaging and 3-D Printing - Also known as cardiac hybrid and fusion imaging, these imaging modalities provide detailed functional and anatomical information about the heart and its associated structures. In the case of heart failure, they provide additional information for patients that require assessment of myocardial viability, blood flow examination, evaluation of valvular abnormalities, and imaging of coronary arteries. These procedures also guide interventional procedures like cardiac resynchronization therapy, revascularisation, aortic valve implantation, etc. Furthermore, they help improve outcomes in heart failure patients by allowing thorough planning of complex procedures and minimizing complications.

Conclusion

Heart failure refers to the inability of the heart to function efficiently. It can be caused due to various factors and, most often, remains undiagnosed until the patient is critical. Symptoms vary from one person to another but range from shortness of breath to swelling of the lower limbs. There are several imaging techniques that not only help diagnose heart failure but also help treat and monitor the response of the treatment. There are no bulletproof solutions or cures for heart failure. Hence, it is extremely crucial to have a healthy lifestyle, consume a balanced meal and get routine health checkups.