Laboratory tests in cardiology

Blood tests are an important part of a cardiac assessment because they help to detect acute and chronic heart disease and play an important role in cardiovascular risk stratification. Although they are not sufficient on their own to make a diagnosis, their results allow the doctor to make decisions about further investigations and treatment.

One of the most important laboratory markers in cardiology is troponin, a marker of heart muscle damage that is key in diagnosing a heart attack but can also be raised in other conditions, such as arrhythmias, heart failure or inflammation of the heart muscle. NT-proBNP is used in the diagnosis and monitoring of heart failure; raised levels indicate strain on the heart muscle.

The lipid profile, which includes total cholesterol, LDL, HDL and triglycerides, plays a major role in cardiovascular prevention. Raised LDL cholesterol is the strongest risk factor for the development of atherosclerosis and coronary heart disease. Blood glucose control and HbA1c levels are also important, because diabetes significantly increases the risk of heart attack and damage to the blood vessels.

Electrolytes are also particularly important, especially potassium and sodium, because an imbalance can lead to heart rhythm disorders or make existing arrhythmias worse. Assessing kidney function through urea, creatinine and the estimated glomerular filtration rate (eGFR) is an essential part of the assessment, especially in patients taking diuretics or other medicines that can affect kidney function. Because thyroid disorders often cause arrhythmias, particularly atrial fibrillation, TSH is also routinely measured in cardiology.

Together, these tests give a complete picture of cardiovascular health and, combined with an ECG, a heart ultrasound and blood pressure measurement, allow a precise and timely assessment of the patient's condition and the planning of optimal treatment.