Diagnostic Evaluation

Patients who present with the first episode of AF should undergo a thorough evaluation to check for the presence of any of the conditions discussed here. In most cases, this requires a comprehensive history and physical examination to rule out precipitating factors such as diabetes and hypertension, a few simple chemical assays including thyroid function tests, and a surface ECG. A transthoracic echocardiogram is also of paramount importance, as AF can be the sole presenting sign of several underlying cardiac diseases—such as cardiomyopathy—as discussed here. Only if all of this diagnostic evaluation is negative, should the patient be given the diagnosis of "lone" AF. If the patient simply has a history of hypertension, for example, this should be considered a sign of structural heart disease. These patients, regardless of age, are at a higher risk for embolic complications, and should be treated differently than patients with true "lone" AF. Other tests that may be useful in the diagnosis and in the management of this arrhythmia are 24-h ambulatory recordings and 30-d event monitors. These tests may help to determine the frequency and duration of asymptomatic episodes of AF which, if present, may impact on therapeutic management. In addition, ambulatory monitoring may determine whether the patient's symptoms are truly secondary to the arrhythmia. Importantly, they may also give the physician a very good idea of how the rhythm begins and terminates, and whether it would be amenable to ablative therapy for a possible cure. For example, if all of the patient's events initiated with atrial flutter degenerating to AF, one may be more prone to treating this patient with radiofrequency ablation of the atrial flutter circuit. On the other hand, if all of the episodes initiated with single premature atrial stimuli that are unifocal in origin, one may consider ablation of the atrial focus. After the diagnosis is made and treatment is initiated, 24-h recordings and event monitors are an essential tool, together with symptom recurrence, to assess the efficacy of therapy.

Tests that generally have limited usefulness in the diagnostic evaluation of AF include stress testing and cardiac catheterization. The yield of these tests is extremely low, and they should not be routinely ordered unless there are other signs and symptoms of CAD. One possible indication for a stress test is for those patients in whom treatment with a class IC antiarrhythmic drug is contemplated. In such patients it is important to rule out significant, unrecognized CAD before starting treatment. It is also important to do a stress test after initiation of therapy, to rule out exercise induced proarrhythmia. In addition to atrial tachycardia or flutter with 1:1 A-V conduction, patients on these agents can develop a wide QRS tachycardia which manifests itself at faster heart rates (a concept known as "use dependence").

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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