There are various types of abnormal heart rhythms, some more serious and permanent than others. Joanne Braham explains the condition and its underwriring implications
Cardiac arrhythmia is a change in regular heartbeat of the heart, usually due to abnormal electrical activity in the heart. The heart may seem to skip a beat, or beat irregularly, very quickly or slowly.
The normal electrical conduction in the heart allows the impulse that is generated by the sinoatrial node (SAN) of the heart to be propagated to and stimulate the myocardium (heart muscle). The myocardium contracts after stimulation. It is this stimulation of the myocardium that allows efficient contraction of the heart, thereby allowing blood to be pumped throughout the body. This generated beat is known as sinus rhythm. An arrhythmia is normally caused when the sinoatrial node misfires. However stress, increased caffeine and alcohol intake can also cause arrhythmias.
Some cardiac arrhythmias are harmless, though annoying, and are not associated with increased mortality, but many of them predispose to adverse outcomes.
For example where there is an insufficient amount of blood transported to the heart because of a weak heartbeat, this may increase the risk of embolisation and stroke, or increase in the risk of heart failure, or sudden cardiac death.
If an arrhythmia results in a heart beat that is too fast, too slow or too weak to supply the body's needs, this manifests as a lower blood pressure and may cause lightheadedness or dizziness, or fainting.
The most common symptom of arrhythmia is an abnormal awareness of heartbeat, termed palpitations. These may be infrequent, frequent, or continuous. One also may experience chest pain, shortness of breath or feeling faint or tired.
The best way to diagnose and assess the risk of any given arrhythmia would be using an electrocardiogram. This trace's the electrical events associated with the contractions of the heart and may identify any abnormalities of heart rate or rhythm, or abnormalities of conduction. If the arrhythmia is intermittent a 24 hour ECG maybe required.
Everyone experiences some variation in their heartbeat at certain times and palpitations can be normal.
Types of cardiac arrhythmia
Arrhythmias can be divided into two main categories: ventricular and supraventricular. Supraventricular arrhythmias occur in the heart's two upper chambers called the atrium. Ventricular arrhythmias occur in the heart's two lower chambers called the ventricles. Supraventricular and ventricular arrhythmias are further defined by the speed of the heartbeats: very slow, very fast and fast uncoordinated. A very slow heart rate is called bradycardia. In bradycardia, the heart rate is less than 60 beats a minute. A very fast heart rate is called tachycardia meaning the heart beats faster than 100 beats a minute. A fast uncoordinated heart rate is called fibrillation. Fibrillation is the most serious form of arrhythmia.
Supraventricular arrhythmia
- Sinus tachycardia - the sinoatrial node sends out electrical signals faster then usual, speeding up the heart rate usually to more than 100 beats a minute. This is a normal response in some situations, such as during exercise, stress or strong emotions. It can also be related to heart disease, respiratory disease and can be induced by excess caffeine, alcohol, cigarettes and certain drugs.
- Paraoxysmal supraventricular tachycardia - a series of early beats in the atria speed up the heart rate. Repeated periods of very fast heartbeats begin and end suddenly.
- Atrial fibrillation - electrical signals in the atria are fired in a very fast, uncontrolled manner. Electrical signals arrive in the ventricles in a completely irregular fashion therefore the heart beat is completely irregular. This condition may cause a blood clot to form in the heart, which can then be transported to other parts of the body, sometimes to the brain where it can cause a stroke.
- Atrial flutter - rapidly fired signals cause the muscles in the atria to contract quickly, leading to a very fast regular heartbeat.
- Sick sinus syndrome - abnormal functioning of the natural pacemaker (the SAN of the heart). This causes episodes of slowing or speeding or even short periods of heart stoppage. It is commonly known as the tachycardia-bradycardia syndrome.
Ventricular arrhythmia
- Premature ventricular complexes - an electrical signal from the ventricles causes an early heartbeat that generally goes unnoticed. The heart then seems to pause until the next beat of the ventricle occurs in a regular fashion.
- Ventricular tachycardia - the ventricles contract rapidly but the rate in the atria remains normal. This usually causes sudden collapse. It often happens after a heart attack.
- Ventricular fibrillation - this is when the whole heart stops beating properly and just flutters. It may follow from ventricular tachycardia. Blood is not circulated to the brain and the rest of the body. If the heartbeat is not rapidly restarted with a defibrillator, death will result. There is a significant risk of recurrence and those without a reversible cause have a recurrence rate in the first year of 35%.
These are some of the most common arrhythmias, varying from the innocent palpitations to the life-threatening arrhythmias.
Statistics
- Arrhythmias are very common and affect over 700,000 people in England.
- Around 50,000 people develop an irregular heartbeat each year in the UK, and it is a major cause of strokes and heart attacks.
- AF affects 5% of the UK population over 65 years of age, rising to 10% in those over 75 years.
- Findings published in the journal Circulation indicate women are at least 30% more likely than men to die early as a result of AF.
- AF is found in 15% of all stroke patients.
- Warfarin treatment can reduce the risk of stroke by 66%.
- Radio frequency ablation of the accessory pathways to treat arrhythmias has a 90% success rate and a low complication rate, according to the Trent Institute for Health Services Research in 1996.
- 22,000 people in the UK are fitted with pacemakers every year to correct cardiac arrhythmias.
- Joanne Braham is underwriter at Aegon Individual Protection
SOURCES
www.mamashealth.com/arrhythmia.asp
www.en.wikipedia.org/wiki/Arrhythmia
hcd2.bupa.co.uk/fact_sheets/html/arrhythmia.html
www.bbc.co.uk
www.wansford.co.uk
www.dcs.gla.ac.uk
www.swissre.com
UNDEWRITING IMPLICATIONS
The underwriting implications for particular conditions are:
- Sinus tachycardia. This may warrant a small rating depending on the number of beats per minute and if the underlying cause established. For elderly lives this would need to be discussed with our Chief Medical Officer
- Paroxysmal supraventricular tachycardia. As long as full cardiac investigations are normal, standard rates can be considered. Insurers may charge a small rating for life and critical illness if the cause is unknown and they suffer less than 10 attacks a year. For other circumstances, each applicant will be assessed on their own merits.
- Atrial fibrillation(AF). For fully investigated cases with no underlying heart disease, minimal attacks and deemed to have paroxysmal AF a small rating could be charged. For older lives with more frequent attacks and deemed to have chronic AF much larger ratings can be applied.
- Atrial flutter. It is assessed in a similar fashion to atrial fibrillation, but underlying heart disease is much more common in this condition.
- Wolff-Parkinson-White syndrome. WPW without a history of AF or paroxysmal supraventricular tachycardia could be considered at standard rates, however with a history of atrial fibrillation without surgical intervention it is possible that terms would not be offered.
- Sick sinus syndrome. Due to risk of sudden death, this would attract a moderate rating unless the patient has had a pacemaker inserted, in which case the insurer may be able to offer better terms. However, it may be necessary to decline offering terms.
- Premature ventricular complexes. For cases that have been fully investigated, then insurers could consider standard rates, otherwise a loading would apply based on the number of premature beats.
- Ventricular tachycardia. This is a more serious arrhythmia and would be postponed for a minimum of two years after the last attack and would then be offered with a large extra if takeable. Critical illness cover would be declined.
- Ventricular fibrillation. Most applications with a history of ventricular fibrillation will be declined.
