Palpitations / Blackouts

 

Palpitations

 

Palpitations are an awarness of the heart beat that is usually uncomfortable

 

Common causes

 

1. Ectopic or extra beats - not harmful but can be uncomfortable

2. An abnormal heart rhythm or "tachycardia" - called a cardiac arrythmia

3. Anxiety with a fast but regular heart beat

4. Anxiety with no cardiac abnormality

 

 

A cardiac arrhythmia is an abnormal heart rhythm.

 

There are two major types

 

Tachycardia 

 

This refers to an abnormal fast heart rhythm. These rhythms can result from the upper chambers (e.g. Inappropriate sinus tachycardia, SVT, atrial tachycardia, atrial flutter, atrial fibrillation) - usually not life threatening. The lower chambers can be the source (e.g. ventricular tachycardia, ventricular flutter, ventricular fibrillation) - usually life threatening. 

 

These have different treatments and some require more urgent intervention. 

 

 

Bradycardia

 

This refers to an abnormal slow heart rhythm. Sinus bradycardia is a slower than normal regular rhythm that normally does not require treatment. 

 

High degree AV block, pauses longer than 3 seconds while awake or 3.5 seconds when asleep will usually require a permanent pacemaker. 

 

Slow rhythms that need a permanent pacemaker often present with symptoms such as dizziness and blackouts.

Blackouts 

 

A blackout is a sudden loss of conciousness. The medical term is syncope. This can be due to a problem with the heart or the brain. 

 

When the heart is the cause it is referred to as cardiogenic or cardiac syncope.

 

Low blood pressure can cause people to feel giddy but does not usually result in a blackout or loss of conciousness. There is usually no loss of conciousness.

 

Neurocardiogenic syncope or "simple fainting" is an important cause of blackouts. There is no heart disease per se. It results from a drop in blood pressure, heart rate or both. These patients normally have a warning and the condition can be managed by maintaining fluids and preventing injury. 

 

Cardiac causes of syncope include

 

1. Cardiac arrythmia (fast or slow heart rhythm)

2. Severe coronary blockages

 

Patients with recurrent blackouts are a candidate for an implantable recorder of heart rhythm. This can remain under the skin for 1 to 2 years to help determine with the heart is the cause of blackouts. 

 

Unfortunately in many cases no cause can be found. Management should focus on reversing the cause if present and preventing injury.