Cardiomegaly is the term given to an enlarged heart due to thickening or dilation of its walls. The enlargement may include the entire heart or any one of its chambers, and it may be temporary or permanent depending upon the cause. The enlargement often occurs as a result of the heart having to bear an increased workload, thus pumping blood harder, as in always having to walk uphill. At other times, the enlargement may be caused by an internal condition of the heart itself.¹

Management or treatment of the advanced cases of cardiomegaly, especially among those patients with a certain condition called dilated cardiomyopathy, requires the use of ventricular assist devices. Ventricular assist devices (VADs) improve blood circulation by supporting heart function, reducing symptoms, and improving the quality of life in patients with severe heart failure. Used often as a bridge to transplant, during the waiting time for heart transplantation, selected patients use them as a destination therapy. A number of trials have shown that VAD improves heart function and reduces symptoms, therefore providing better survival rates. However, complications like thromboembolism, hemolytic anemia, and renal failure indicate their management should be cautious. Consequently, VAD technology is in a continuous state of improvement to make these devices highly significant in the management of severe cardiomegaly and the improvement of patient outcomes.²

Understanding enlarged hearts

Symptoms of an enlarged heart, or cardiomegaly, include dizziness, swelling in the legs, feet or abdomen, tiredness, fluttering heartbeat, low energy and shortness of breath, although for some people there are no symptoms. Causes for an enlarged heart include any condition that causes the heart to work harder, such as coronary artery disease, anemia, pregnancy, heart rhythm disorders, cardiomyopathy, hypertension, and several lung diseases. This may happen naturally in sportsmen as a result of hard work, but in the majority of cases, the heart, though enlarged, performs its function worse.¹

Health care professionals can diagnose an enlarged heart when they go over symptoms, their family health history, and exercise background. A heart murmur or signs of heart failure may be revealed by a physical examination alone. Chest X-rays, cardiac CT scans, and echocardiograms are diagnostic tests that will be able to show the size and functioning of the heart. Other supportive tests include EKGs, heart MRIs, stress tests, and even genetic testing to confirm diagnosis and underlying causes. These tests clarify the structure, function of the heart, and those conditions that may have led to or contributed to this disease, thus guiding further treatment decisions.¹

The role of advanced cardiac devices

Advanced cardiac devices are important in the management of enlarged hearts through the provision of vital support when the heart cannot function adequately by itself. This reduces complications, hence improving quality of life. The devices address a wide range of problems associated with weakened heart function and give patients healthier and more active lives. Pacemakers, for example, regularise abnormal heart rhythms (arrhythmias) by maintaining a normal heartbeat; this relieves the heart and minimises symptoms such as fatigue and dizziness. Implantable cardioverter-defibrillators (ICDs) stand guard, finding any potentially lethal arrhythmias and correcting them with an electric shock to avoid sudden cardiac arrest.³

VADs provide mechanical pumping to patients with advanced heart failure to maintain blood flow and alleviate symptoms of heart failure. Biventricular pacemakers and CRT devices function by resynchronising the contractions of the heart, thus profoundly improving the efficiency of blood pumping in patients with heart failure.³

These devices are implanted with minor surgery, requiring ongoing monitoring to optimise the function of the device and to make necessary adjustments. Advancing technology in the devices themselves, including remote monitoring, smaller device sizes, and extending battery life, continues to improve patient outcomes and quality of care. With such developments, cardiac devices remain an indispensable element of the treatment of conditions like cardiomegaly and offer symptomatic relief in addition to long-term therapeutic benefits in leading a long and healthy life.³

Types of advanced cardiac devices

Advanced heart failure, especially those with reduced ejection fraction heart failure, requires the symptomatic use of advanced cardiac devices for the prevention of arrhythmias and overall outcome improvement. Examples of such devices include ICDs, CRT-Ps, and CRT-Ds.⁴

These devices are designed to prevent sudden cardiac death from potentially lethal arrhythmias. They monitor the heart rhythm and, in the case of an arrhythmia, can deliver anti-tachycardia (ATP) pacing or SHOCKS. ICDs are primarily indicated in patients with HF that present with low ejection fraction, left ventricular ejection fraction (LVEF) less than 35%, who are at risk of fatal ventricular arrhythmias. Both are appropriate for secondary prevention-that is, in patients with a known history of life-threatening arrhythmias-and also for primary prevention, for those not with such a history but at high risk.⁴

CRT is a treatment for patients with symptomatic heart failure resulting from asynchronous electrical and mechanical activation of the heart, which usually emanates from LBBB. The devices improve symptoms and functional status by resynchronising contractions at both ventricles. CRT-D combines the functions of CRT and ICD, providing both cardiac resynchronisation and prevention of sudden death due to fatal arrhythmias. CRT is indicated in symptomatic patients in NYHA classes III-IV with LVEF less than 35% and a QRS duration greater than 120 ms, especially with left bundle branch block (LBBB) morphology.⁴

The choice between CRT-P and CRT-D depends on the presence or otherwise of ventricular arrhythmias. The first one is preferred in cases when the patient is under higher risk of arrhythmias, while for patients who are out of such risk, CRT-P may be sufficient. Device therapy, in turn, carries risks related to infection, lead failure, and procedural complications.⁴

Benefits of cardiac devices for enlarged hearts

Advanced cardiac devices offer considerable benefits to patients with cardiomegaly, particularly with heart failure. ICDs play a significant role in the prevention of sudden cardiac death in patients with reduced LVEF. Such devices reduce mortality in high-risk patients by more than 50%. Cardiac resynchronisation therapy devices have been highly important in symptom improvement, exercise capacity, and left ventricular function, and have reduced heart failure hospitalisations and all-cause mortality. CRT alone decreased the risk of death by 24%, while with the addition of a defibrillator, the risk was decreased by 36% (CRT-D). Moreover, pacemakers can regulate heart rhythm, and their upgrade to a CRT device is easy in case of such need; hence, further improvement of patients' condition is possible.⁵

The left ventricular assist devices showed a 47% reduction in mortality among patients with end-stage heart failure compared to conventional medical care and proved to be an important option for such cases at advanced stages of the disease. These devices can remarkably improve the quality of life through better cardiac output, mitigation of symptoms, and improved survival. Ongoing research is focused on continuing refinement of device programming and is directed at the development of more sophisticated monitoring systems that could detect early signs of heart failure decompensation. As such, these devices, as they continue evolving, have even greater promise in the management of advanced heart failure and in further improving patient outcomes.⁵

Challenges and considerations

Advanced cardiac devices offer considerable advantages to patients with enlarged hearts, as well as those suffering from other forms of cardiac conditions. At the same time, however, they also pose quite a number of complications and risks. Among them are immediate post-procedure complications such as pneumothorax, cardiac perforation, pocket haematomas, lead displacement, and infection - a very grave risk. The infection rate is 4.82/1000 device-years after primary implantation and 12.12/1000 device-years after replacement, from superficial to systemic infections. Device related limitations also entail regular follow up and possibly remote monitoring. The health economic burdens related to the device, especially device infection, are also very relevant. The general practitioner should therefore be aware of cardiac implantable electronic device (CIED) infection presentation such as persistent pyrexia or discomfort over the site of the device, and use simple blood tests such as FBC and CRP, which will help in diagnosis. These factors must be considered in the decision-making regarding device implantation and the management of the patients thereafter.⁵

Conclusion

The management of an enlarged heart, or cardiomegaly, is important for better patient outcomes. Advanced cardiac devices have contributed much to this process. Devices such as pacemakers, ICDs, CRT devices, and VADs guarantee not only improved life expectancy but also reduced symptoms of heart failure, thus enabling patients to lead more active and healthy lives. These devices have become indispensable for patients with advanced heart failure because they improve circulation, resynchronise heart rhythms, and avoid sudden cardiac arrest. As technology continues to evolve, we can expect even greater improvements in device functionality, including better monitoring and more personalised treatments. People with heart conditions should seek care as early as possible and consult options with their healthcare professional. This early intervention with advanced cardiac devices improves the quality of life and enhances long-term survival for patients with enlarged hearts.