Palpitations are an abnormality of heartbeat characterized by simultaneous awareness of
one’s pulse and discomfort.
They can be accompanied by dizziness or difficulty breathing.
They might or might not be associated with skipped beats and/or accelerated heart rate.
Palpitations are a symptom reported by the patient and not a medical diagnosis.
Palpitations are common and occur in most individuals with healthy hearts.
Palpitations without underlying heart disease are generally considered benign.
However, heart palpitations can be a symptom of a serious illness such as coronary heart
disease, asthma, or emphysema.
Patients can notice palpitations through abnormal or normal awareness.
The difference between an abnormal awareness and a normal awareness is that the former
interrupts other thoughts, whereas the latter is almost always caused by a concentration
on the beating of one's heart.
Palpitations should not be confused with single missed/skipped beats or isolated jolts in
the chest, which are normally regarded as ectopic beats.
Palpitations may be brought on by overexertion, stress, anxiety, panic, adrenaline, alcohol,
nicotine, caffeine, cocaine, amphetamines, and other drugs, previous chest surgery, disease
and many other factors.
It can also happen in mitral stenosis.
Palpitations may be associated with heart problems, but also with kidney disease, electrolyte
imbalances for magnesium, potassium and calcium, thyroid malfunction, asthma, and deficiencies
or lowered stores of certain nutrients which may include, but are not limited to, taurine,
arginine, iron, potassium and magnesium.
Attacks can last for a few seconds or hours, and may occur very infrequently, or more than
daily.
Palpitations alongside other symptoms, including sweating, faintness, frequent headaches, chest
pain or dizziness, indicate irregular or poor heart function and should be investigated
by a medical professional.
Palpitations may also be associated with anxiety and panic attacks, in which case psychological
assessment is recommended.
This is a common disorder associated with many common medications such as anti-depressants.
Palpitations can also occur from blood loss, excessive pain, or lack of oxygen.
Causes Palpitations can be attributed to one of four
main causes: Extra-cardiac stimulation of the sympathetic
nervous system, can be caused by anxiety and stress due to acute or chronic elevations
in glucocorticoids and catecholamines.
Gastrointestinal distress such as bloating or indigestion, along with muscular imbalances
and poor posture, can also irritate the vagus nerve causing palpitations)
Sympathetic overdrive, anemia, heart failure, mitral valve prolapse).
Hyperdynamic circulation.
Cardiac dysrhythmias.
Anxiety and stress Anxiety and stress elevate the body's level
of cortisol and adrenaline, which in turn can interfere with the normal functioning
of the parasympathetic nervous system resulting in overstimulation of the vagus nerve.
Vagus nerve induced palpitations are felt as a thud, a hollow fluttery sensation, or
a skipped beat, depending on at what point during the heart's normal rhythm the vagus
nerve fires.
In many cases, the anxiety and panic of experiencing palpitations causes a sufferer to experience
further anxiety and increased vagus nerve stimulation.
The link between anxiety and palpitations may also explain why many panic attacks involve
an impending sense of cardiac arrest.
Similarly, physical and mental stress may contribute to the occurrence of palpitations,
possibly due to the depletion of certain micronutrients involved in maintaining healthy psychological
and physiological function.
Gastrointestinal bloating, indigestion and hiccups have also been associated with overstimulation
of the vagus nerve causing palpitations, due to branches of the vagus nerve innervating
the GI tract, diaphragm, and lungs.
Symptoms Many times, the person experiencing palpitations
may not be aware of anything apart from the abnormal heart rhythm itself.
But palpitations can be associated with other things such as tightness in the chest, shortness
of breath, dizziness or light-headedness.
Depending on the type of rhythm problem, these symptoms may be just momentary or more prolonged.
Actual blackouts or near blackouts, associated with palpitations, should be taken seriously
because they often indicate the presence of important underlying heart disease.
Another symptom is pain in arms or legs sometimes lasting through the night after the palpitation.
Diagnosis The most important initial clue to the diagnosis
is one's description of the palpitations.
The approximate age of the person when first noticed and the circumstances under which
they occur are important, as is information about caffeine intake, and whether continual
palpitations can be stopped by deep breathing or changing body positions.
It is also very helpful to know how they start and stop, whether or not they are regular,
and approximately how fast the pulse rate is during an attack.
If the person has discovered a way of stopping the palpitations, that is also helpful information.
The diagnosis is usually not made by a routine medical examination and electrical tracing
of the heart's activity, because most people cannot arrange to have their symptoms be present
while visiting the doctor.
Nevertheless, findings such as a heart murmur or an abnormality of the ECG, which could
point to the probable diagnosis, may be discovered.
In particular, ECG changes that can be associated with specific disturbances of the heart rhythm
may be picked up; so routine physical examination and ECG remain important in the assessment
of palpitations.
Blood tests, particularly tests of thyroid gland function are also important baseline
investigations.
The next level of diagnostic testing is usually 24 hour ECG monitoring, using a form of tape
recorder called a Holter monitor, which can record the ECG continuously during a 24-hour
period.
If symptoms occur during monitoring it is a simple matter to examine the ECG recording
and see what the cardiac rhythm was at the time.
For this type of monitoring to be helpful, the symptoms must be occurring at least once
a day.
If they are less frequent, the chances of detecting anything with continuous 24, or
even 48-hour monitoring, are substantially lowered.
Other forms of monitoring are available, and these can be useful when symptoms are infrequent.
A continuous-loop event recorder monitors the ECG continuously, but only saves the data
when the wearer activates it.
Once activated, it will save the ECG data for a period of time before the activation
and for a period of time afterwards - the cardiologist who is investigating the palpitations
can program the length of these periods.
An implantable loop recorder may be helpful in people with very infrequent, but disabling
symptoms.
This recorder is implanted under the skin on the front of the chest, like a pacemaker.
It can be programmed and the data examined using an external device that communicates
with it by means of a radio signal.
Investigation of heart structure can also be important.
The heart in most people with palpitations is completely normal in its physical structure,
but occasionally abnormalities such as valve problems may be present.
Usually, but not always, the cardiologist will be able to detect a murmur in such cases,
and an ultrasound scan of the heart will often be performed to document the heart's structure.
This is a painless test performed using sound waves and is virtually identical to the scanning
done in pregnancy to look at the fetus.
Treatment Treating palpitations will depend on the severity
and cause of the condition.
Palpitations that are caused by heart muscle defects will require specialist examination
and assessment.
Palpitations that are caused by vagus nerve stimulation rarely involve physical defects
of the heart.
Such palpitations are extra-cardiac in nature, that is, palpitations originating from outside
the heart itself.
Accordingly, vagus nerve induced palpitations are not evidence of an unhealthy heart muscle.
Treatment of vagus nerve induced palpitations will need to address the cause of irritation
to the vagus nerve or the parasympathetic nervous system generally.
It is of significance that anxiety and stress are strongly associated with increased frequency
and severity of vagus nerve induced palpitations.
Anxiety and stress reduction techniques such as meditation and massage may prove extremely
beneficial to reduce or eliminate symptoms temporarily.
Supplementation with certain nutrients such as taurine, citrulline, GABA, and magnesium
may also provide some reduction in nervous tension and anxiety, which in turn can help
reduce symptoms.
Changing body position may also help reduce symptoms due to the vagus nerve's innervation
of several structures within the body such as the GI tract, diaphragm and lungs.
With respect to the hyperstimulation of the vagus nerve, anticholinergic agents such as
antihistamines or tricyclic antidepressants may inhibit the effect of acetylcholine in
activating the vagus nerve thereby reducing its interference on the heart's normal rhythm.
See also Cardiac dysrhythmia
References
External links Medic8 Family Health Guide
MedlinePlus Medical Encyclopedia, NIH Arrhythmia
Heart Palpitations Irregular heartbeat
Abnormal Heart Rhythm