Dr. M.J. Bazos, MD
Patient Handout
HEART BLOCK,
SECOND-DEGREE
About Your
Diagnosis
Heart block refers to
a delay of conduction of electrical signals from the atrium through the
atrioventricular node (part of the electrical wiring of the heart). This node
carries the electric signals from the atria that tell the ventricles to
contract. The block can affect different parts of the conduction system of the
heart. It is generically referred to as heart block, and there are many
different types of blocks of electrical signals in the heart. Second-degree
heart block affects the node (type I block) or conduction below the node (type
II block). The atria contract normally, but because they do not receive the
proper signal, the ventricles may not contract as often as they are supposed
to.
Living With Your
Diagnosis
Symptoms of heart block
relate to insufficient pumping of blood from the heart. Heart block may produce
no symptoms. Often it can cause extreme fatigue, lightheadedness, or syncope
(fainting). Severe heart block can cause angina (chest pain) or stroke (not
enough blood flow to the brain). Heart block is relatively common. About one
half of persons with heart block have no known cause. Most of the others have
some form of heart disease. They may have had damage to the heart from a heart
attack (myocardial infarction) or myocarditis (inflammation of the heart
muscle). Heart block may come from overdosing of digitalis medications
(digoxin). It may also be caused by some a congenital heart abnormality (one
that one is present at birth). Heart block is detected with an electrocardiogram
(ECG). Usually the patient has normal impulses from the atrium, but there is
evidence that some of the impulses do not reach the ventricles. A patient with
type I second-degree heart block may have no symptoms. Type II block is usually
the result of heart disease. Patients with type II block are at risk for
complete heart block, cardiomyopathy (disease of the heart muscle), or death
from asystole (the heart not beating). Medications that cause the condition have
to be stopped or
changed.
Treatment
If
you have type I block and have no symptoms and no heart disease, no treatment is
required. Patients ith either type of heart block or those who have symptoms
because the ventricle is not beating fast enough to meet blood demands may need
a pacemaker (Fig 1). A pacemaker is an electrical device with a wire to the
heart muscle that signals the ventricles to contract regularly (fixed-rate
pacers) or to beat faster in response to increased activity (demand pacers). The
pacemaker may be external with the wire entering through a vein, or it may be
implanted in the patient with a minor operation. Older pacemakers were
susceptible to damage from microwaves and strong electronic equipment. New
pacemakers are safer and more reliable. You must still exercise caution around
strong magnetic or ultrasonic forces such as those used in some physical therapy
settings or in airport security screens. If you have a pacemaker, you will be
given instructions by the cardiologist regarding maintenance and care of the
pacemaker.
The
DOs
• Make your diet one for a
healthy heart, which means make it low in fat and cholesterol. Lose weight and
stop smoking.
• Continue other
medical treatments as directed.
The
DON’Ts
• Do not exercise
until you have clearance from your
physician.
When to Call Your
Doctor
• If you have worsening
dizziness, fainting, chest pain, or shortness of breath.