Dizzy when you stand up? Can this lead to atrial fibrillation?

This study examined whether postural hypotension (low blood pressure associated with standing up) increases the occurrence of atrial fibrillation. 

Many have experienced at sometime in their lives a dizzy or a lightheaded sensation after standing up from sitting or lying down. This sensation is known as postural hypotension (also known as orthostatic hypotension) and is caused by a drop in blood pressure. To counteract low blood pressure the heart must beat faster and the blood vessels (tubes that carry blood through the body) must tighten. Postural hypotension is often mild, lasting only a few seconds. However, sustained postural hypotension can lead to an irregular heart beat condition known as atrial fibrillation (AF) which may weaken the heart and lead to heart failure.

This study looked at whether measuring the blood pressure change from lying down to standing can be a sign of whether a patient has a higher risk of AF. 

The study was carried out on 12,071 participants of African American or Caucasian race aged 45-64 years. Blood pressure (the force of the blood pushing against the walls of the blood vessel) was measured in millimeters of mercury (mm Hg). For blood pressure readings two numbers are shown – the top number which measures the pressure in the arteries when the heart is beating (systolic blood pressure: SBP) and the bottom number which measures the pressure in the arteries when the heart is relaxing or filling (diastolic blood pressure: DBP). Blood pressure is considered normal at around 120/80 mmHg.

At the beginning of the study blood pressure was measured after 20 minutes of lying down with the face pointing upwards. Postural hypotension was defined as a SBP drop of >20 mmHg or >10 mmHg drop in DBP when changing position from lying to standing. AF was identified using an electrocardiogram that measures electrical activity in the heart, hospital records or death certificates. Average follow-up was 18.1 years.

At the beginning of the study 5% of patients had postural hypotension. 11.5% of patients developed AF during follow-up. AF occurred more commonly among those with postural hypotension than those without. When other risk factors for AF were also taken into account, postural hypotension was associated with a 40% increased risk of AF development.

This study concluded that postural hypotension is associated with a higher risk of developing atrial fibrillation.

The causes of low blood pressure can range from dehydration to serious medical disorders. In this study, postural blood pressure change was only measured upon three visits across the course of 18 years, hence how this reliably reflects blood pressure for the rest of the time is uncertain.

If you are experiencing postural hypotension, check with your doctor to see what treatment or preventative options are available.