Cardiac catheterization and biopsy: In this procedure, a thin tube (catheter) is inserted into the groin and threaded through the blood vessels to the heart, where a small sample (biopsy) of the heart, if indicated, can be extracted for laboratory analysis. For deceased people, cardiomegaly at autopsy has been suggested when the heart weighs more than >399 grams in women and >449 grams in men. Classification
Cardiomegaly can be classified by the main enlarged location of the heart, and/or by the structure of the enlargement. There are also specific additional subtypes. For example, the athletic heart syndrome is a non-pathological condition commonly seen in sports medicine in which the human heart is enlarged, and the resting heart rate is lower than normal. By enlarged location
Ventricular hypertrophy
Left
Right / Cor pulmonale
Atrial enlargement
Left
Right

Structure of enlargement
Dilated cardiomyopathy is the most common type of cardiomegaly. In this condition, the walls of the left and/or right ventricles of the heart become thin and stretched. The result is an enlarged heart.In the other types of cardiomegaly, the hearts large muscular left ventricle becomes abnormally thick. Hypertrophy is usually what causes left ventricular enlargement. Hypertrophic cardiomyopathy is typically an inherited condition. Treatment
Treatments for cardiomegaly include a combination of medication treatment and medical/surgical procedures. Below are some of the treatment options for individuals with cardiomegaly:
Medications

Diuretics: to lower the amount of sodium and water in the body, which can help lower the pressure in the arteries and heart. Angiotensin-converting enzyme (ACE) inhibitors: to lower the blood pressure and improve the hearts pumping ability.
For some people cardiomegaly is a temporary condition, which can resolve on its own, making ones lifestyle normal like before. Others may have a permanent enlargement, which would then need to be taken care of by the above treatment options.Lifestyle changes

Smoking cessation
Limiting alcohol and caffeine intake
Maintaining a healthy weight
Increasing fruits and vegetables in a daily diet
Limiting consumption of high-fat and/or high-sugar foods
Getting adequate restful sleep

References
Further reading
Amin, Hina; Siddiqui, Waqas J. (2019). "Cardiomegaly". StatPearls. StatPearls Publishing. PMID 31194436. Ampanozi, Garyfalia; Krinke, Eileen; Laberke, Patrick; Schweitzer, Wolf; Thali, Michael J.; Ebert, Lars C. (1 September 2018). "Comparing fist size to heart size is not a viable technique to assess cardiomegaly". Cardiovascular Pathology. 36: 1–5. doi:10.1016/j.carpath.2018.04.009. PMID 29859507. S2CID 44086023. Agostoni, PierGiuseppe; Cattadori, Gaia; Guazzi, Marco; Palermo, Pietro; Bussotti, Maurizio; Marenzi, Giancarlo (1 November 2000). "Cardiomegaly as a possible cause of lung dysfunction in patients with heart failure". American Heart Journal. 140 (5): A17–A21. doi:10.1067/mhj.2000.110282. PMID 11054632. Luedde, Mark; Katus, Hugo; Frey, Norbert (1 January 2006). "Novel Molecular Targets in the Treatment of Cardiac Hypertrophy". Recent Patents on Cardiovascular Drug Discovery. 1 (1): 1–20. doi:10.2174/157489006775244290. PMID 18221071. External links

American Heart Association