Investigations in a Patient with Atrial Fibrillation

Every patient with newly diagnosed atrial fibrillation (AF) must undergo a comprehensive evaluation in order to

diagnose comorbidities and
identify risk factors.

One of the main pillars of AF management is the treatment of comorbidities and risk factors. Comprehensive AF management follows the SKC algorithm:

S (Stroke) – prevent stroke
K (Keep the Sinus rhythm) – maintain sinus rhythm
C (Comorbidities and Risk factors) – management of comorbidities and risk factors

Newly diagnosed AF may occur spontaneously or as a consequence of a trigger. This trigger may also precipitate AF in the future. A trigger may be:

A risk factor:

Alcohol excess, excessive stress, energy drinks, coffee, etc.

A comorbidity that is untreated or inadequately treated:

Hyperthyroidism, anaemia, arterial hypertension, obesity, heart failure, inflammation, etc.

Infographic illustrating the basic diagnostic workup in newly diagnosed atrial fibrillation, including ECG, laboratory tests, echocardiography, and exercise testing.

Investigations in a Patient with Newly Diagnosed Atrial Fibrillation

Class

In every patient with newly diagnosed AF, the following investigations are recommended:

Blood pressure measurement
BMI assessment
Laboratory tests
12-lead ECG
Transthoracic echocardiography
Exercise testing or CT coronary angiography

A comprehensive evaluation in a patient with newly diagnosed AF is essential, as the patient’s symptoms may not be caused by AF. For example, a patient may have AF and dyspnoea, but the dyspnoea may be due to anaemia rather than AF.

Hemodynamically unstable newly diagnosed AF requires urgent treatment and often hospitalization.

The following table summarizes the basic investigations in a patient with newly diagnosed AF.

Basic Investigations in Newly Diagnosed Atrial Fibrillation
12-lead ECG	During AF, focusing on: Ventricular rate During sinus rhythm, focusing on: Left ventricular hypertrophy (Sokolow index) Left atrial enlargement (P mitrale)
Laboratory tests	Laboratory tests focusing on: Anaemia (haemoglobin) Inflammation (CRP) Complete blood count Renal disease (urea, creatinine) Liver disease (ALT, AST, GMT, ALP, bilirubin, albumin) Diabetes mellitus (fasting glucose, HbA1c) Thyroid disease (fT4, TSH) Minerals (K, Na, Mg, Ca, P) Coagulation (INR, Quick) Heart failure (NT-proBNP) Thromboembolism (D-dimer) Thrombophilic states (if suspected)
Transthoracic echocardiography (TTE)	TTE focusing on: Ejection fraction Left atrial size Mitral stenosis Left ventricular hypertrophy Left atrial thrombus Dilated cardiomyopathy Amyloidosis
Exercise testing (stress ECG)	Focusing on: Coronary artery disease
CT coronary angiography	Focusing on: Coronary artery disease

If there is a specific indication in AF, the following extended investigations are performed.

Extended Investigations in Atrial Fibrillation
Transoesophageal echocardiography (TEE)	Focusing on: Spontaneous echo contrast in the left atrium Left atrial appendage emptying velocity Left atrial thrombus
Selective coronary angiography	Focusing on: Coronary artery disease
Percutaneous coronary intervention (PCI)	In confirmed coronary artery disease indicated for PCI.
Cardiac MRI	Focusing on: Amyloidosis
Brain CT (angiography)	Focusing on: Transient ischaemic attack (TIA) Ischaemic stroke
Brain MRI	Focusing on: Chronic ischaemic changes Microbleeds Lacunar infarcts Cerebral atrophy Silent infarcts