PCL 1: Definition and DDx

PCL Week 1: Frank’s out of rhythm.

Definition of atrial fibrillation: a type of supraventricular arrhythmia that originates from the atria (Lim, et. al 2007).

• · An abnormal rhythm that originates from the atria of the heart.
• · According to Lim (et. al 2007) atrial fibrillation occurs in hearts that are enlarged, or diseased.

DDx for Frank:

· Atrial flutter: similar to atrial fibrillation (though less common). Condition where electrical discharge by the atria is increased (250-350 impulses/min) but not all impulses are conducted to the ventricle (only every 2^nd, 3^rd, or 4^th impulse will be conducted (Lim, et. al 2007).

o Diagnosis: shows characteristic ECG

· Sinus tachycardia: sinus rate (normal regular heart rhythm) is faster than usual. Cause is normally other underlying pathology, ie: pain, fever, stress, myocardial ischemia, pulmonary oedema, hypoxia, anemia, hyperthyroidism, medication, drugs. Can be quite normal in young children (Bollinger and Heidenreich).

o Diagnosis: related to P wave

o Treatment: directed at the underlying cause.

As Frank had no P wave, can probably rule sinus tachycardia, and the above listed underlying pathologies, out of the DDx.

· Junctional arrhyhmias: additional pathway of conduction tissue exists b/w atrium and ventricle. When an impulse travels from atria to atrioventricular node, it is able to re-enter the atrium via the additional pathway. The impulse will also continue down through the bundle of His. Generates a complex tachycardia (Lim et. al 2007).

o Symptoms: with onset see palpitations and syncope.

o Presence of P wave suggests this is not Frank’s diagnosis

· Ventricular tachycardia: increased ventricular rhythm. Can occur as a result of infarction, ischemic heart disease, ventricular aneurism, heart valve disease (Lim et. al 2007).

o Diagnosis: ECG

o Symptoms include palpitations, and collapsing; possible DDx for Frank, as are the underlying pathologies listed.

· Anxiety: symptoms include palpitations, anxiety, gastric disturbance, breathlessness, sweating, trembling, etc (Ropper and Samuels 2009)

As Frank is only exhibiting palpitations and dizziness, and given Hx in the case, can probably rule out anxiety as the cause of his current condition.

· Hyperthyroidism: symptoms can include sweating, weight loss/gain, irritability, fatigue, palpitations. Condition where there is an imbalance in the thyroid hormones T4 or/and T3 (Fitzgerald 2010).

Frank fits the category for weight gain and palpitations, however there was nothing in this source about dizziness.

References:

Lim, E Loke, YK & Thompson, A 2007. Medicine and Surgery an Integrated Textbook, Elsevier Limited.

Bollinger, BC & Heidenreich J. Current diagnosis and treatment: Emergency Medicine, Access Medicine.

Ropper, AH & Samuels, MA 2009. Adams and Victor’s Principles of Neurology, Access Medicine.

Fitzgerald, PA 2010. Current Medical Diagnosis and Treatment, Access Medicine.