An ECG records the electrical signal generated by the heart and is performed by applying up to 12 metal plates (electrodes) to the chest, wrists and ankles. In CM, the ECG is usually abnormal, perhaps with only slight changes, sometimes even before, for example, hypertrophy develops, in Hypertrophic Cardiomyopathy (HCM).

It allows a continuous recording of the electrocardiogram for 24/48 hours, and even more, if necessary, by means of a cassette recorder, which is worn around the neck. The ECGD (also called Holter) highlights any irregularities in the heartbeat (arrhythmias), which manifest themselves as palpitations, and are due to early beats (extrasystoles) or other arrhythmias, the most important of which are atrial fibrillation (AF) and non-sustained ventricular tachycardia (NSVT). In some cases it can demonstrate episodes of reduced oxygen supply to the heart (ischemia) which are associated with “angina”.

Chest pain (angina), the development of a “gradient” in the CMI, or of arrhythmias induced by effort and the possible efficacy of the therapy can be evaluated by means of a progressive effort that can be performed on a bicycle (seated or lying on a bed), or on a treadmill.

TS can also be performed simultaneously with the measurement of oxygen consumption and carbon dioxide production during progressive effort (Cardiopulmonary or Cardiorespiratory Test). In this way it is possible to verify how much CM reduces the exercise capacity and limits the patient's daily or work activities. TCP can also be associated with ECHO or cardiac catheterization (see later)

The ECHO has been in use for about 50 years and has allowed to “discover” CM easily. Through ultrasound the ECHO produces an image of the heart in motion, and allows to measure the thickness of the walls and how the walls move, if the cavities (ventricles and atria) are normal, large or small. A part of the exam, called COLOR DOPPLER, produces a color image, which represents the blood flow inside the heart and allows to evaluate not only if the heart valves are normal or altered but also to calculate the pressures inside the heart cavities (the difference in pressure between 2 zones is called gradient)

In CM, CMR allows for detailed examination of cardiac structures, particularly the walls and dimensions of the right ventricle (RV), which is difficult to see with ECHO. Contrast media can highlight areas within the cardiac muscle that present “fibrosis,” or scars.

It has some limitations: the duration of the examination is long (from half an hour to 1 hour) and people with old pacemakers, or automatic defibrillators, prostheses or pieces of metal cannot undergo this examination.

In patients whose diagnosis is still uncertain or who do not improve with medical therapy, it may be necessary to perform a cardiac catheterization. In this test, a very thin tube (catheter) is passed from a vein or artery (from the arm) and pushed up to the heart, with the guidance of X-rays. It allows to measure the pressures inside the heart and in the lungs, at rest or under stress or pharmacological stimulus, to accurately evaluate the function of the left ventricle (LV) and any valvular insufficiencies.

For patients with angina or life-threatening arrhythmias, it is necessary to visualize the coronary arteries by injecting a liquid (contrast medium) into a vein (coronary CT angiogram), or into an artery in the wrist or groin (coronary angiography). It can then be seen if they are blocked or if there are congenital anomalies.

Cardiac catheterization can also be performed to stimulate the heart and try to induce cardiac arrhythmias, to locate and observe any frequent arrhythmias (e.g. very frequent extrasystoles, atrial fibrillation or flutter, sustained ventricular tachycardia). It is a rarely necessary test, usually recommended in that minority of patients who have frequent and/or significant arrhythmias or repeated fainting (Syncope). It can also be used to test the effectiveness of an implantable defibrillator, transvenous (T ICD) or subcutaneous (S ICD)

Thallium or technetium scintigraphy is not indicated in patients with CM.

In some patients, particularly with HCM and angina, it may be useful to perform a (positron emission tomography, “PET”) to evaluate the amount of maximal flow in the various sections of the heart, after pharmacological stimulation (usually “Dipyridamole”). Generally in patients with HCM this value is reduced, in some areas even markedly, where “fibrosis” has developed or will develop, i.e. an area with scarring, which can be documented with CMR.

To distinguish CMI from cardiac transthyretin amyloidosis, a myocardial scintigraphy with bone tracer is indicated.

If CM is suspected to be genetic in origin, it is advisable to ascertain whether CM, even in a different or initial form, is present in first-degree relatives (parents, brothers and/or sisters, children). In this case, both ECG and an “accurate” ECOCOLOR DOPPLER test must be done (one of the two alone is not sufficient) at least every 3 years or so.

If the gene that caused CM has already been identified with genetic analysis, it is possible to search for the same gene in first-degree relatives in adults together with ECG and ECHO. In children, it is usually necessary to wait until they are 18 years old, unless they want to engage in competitive sports.