About cardiac arrythmia
Cardiac arrythmia is a heart problem characterised by abnormal
electrical activity in the heart resulting in its disorderly rhythm.
The heart consists of two upper chambers namely atria and two lower
chambers namely ventricles, which contract in a coordinated fashion. The
signal for contraction of heart muscles, also called electrical
impulse, begins in the SA node (pacemaker) placed in one of the atria.
This electrical impulse is then passed along atria and ventricles,
resulting in synchronised heart beats. The normal heart rate is 72
regular beats per minute.
Any disorder in the electrical conduction of impulses may result in
un-coordinated or abnormal rhythm of heart, called arrythmias. At times,
the heart rate may be regular but slower than 60 beats per minute and
is termed as bradycardia whereas heart rate of more than 100 per minute
is called tachycardia.
Cardiac arrythmia: Incidence, age and sex
Cardiac arrythmias are commonly seen in the general population.
Although it can occur in any age group, it is predominantly seen in
Signs and symptoms of cardiac arrythmia: Diagnosis
Cardiac arrythmias has a varied clinical spectrum. Some individuals
may be asymptomatic or experience occasional episodes of palpitations
and skipping beats. However cardiac arrythmias in some individuals may
present with breathlessness, fainting spells, increased sweating and
fatigue. Following are some examples of cardiac arrythmia encountered in
the general population:
- Atrial Fibrillation- Rapid, irregular rhythm of upper chambers of heart.
- Atrial Flutter- Similar to atrial fibrillation but more synchronised.
- Supraventricular tachycardia- Rapid but regular heart rate in atria.
- Ventricular Fibrillation- Erratic, irregular rate originating in the
lower chambers of heart called ventricles. The heart is unable to pump
out blood to other organs. This is a medical emergency.
- Bradyarrythmias- Slow heart rate which can be either regular or irregular.
It is essential to consult a cardiologist when an individual
experiences the above stated symptoms. Cardiac arrythmia can be
diagnosed by auscultation of the chest during physical examination.
However, other investigations like ECG, ambulatory cardiac monitoring,
stress tests and electrophysiology studies may be needed to establish
the type of cardiac arrythmia.
Causes and prevention of cardiac arrythmia
Several causes of cardiac arrythmia have been postulated including
drugs and other diseases. Coronary artery disease of heart or angina may
predispose to cardiac arrythmia in many individuals. Furthermore,
kidney diseases or severe dehydration may also result in arrythmia in
response to electrolyte imbalance. Certain medications like beta
blockers or psychotropics are also offending factors in causations of
Some preventive measures include maintaining optimal weight, regular
physical exercises, appropriate dietary habits, smoking cessation and
reduction in stress level.
Cardiac arrythmia: Complications
The complications of cardiac arrythmia include partial or complete
heart block characterised by failure of conduction of electrical
impulses within the heart. This is a serious condition which demands
immediate medical attention. Other complications are also fatal and
include heart attack, stroke or sudden death.
Cardiac arrythmia: Treatment
The goal of treatment is to regularize and stabilize the rhythm of
the heart. This can be done by medications, using electric current or by
implanting a pacemaker. Medications like anti-arrythmic drugs may be
prescribed to normalise the heart rate. Other medications like
anti-coagulants may also be used to prevent clotting of blood which may
occur due to erratic pumping by the heart. Defibrillation procedure
which uses electric shock may be considered in management of ventricular
fibrillation. In some individuals, pacemaker can be implanted which
will send renewed electric signals to the heart muscles. Other
modalities of treatment include cardioversion and radiofrequency