- Palpitation is one of the common symptoms for which cardiac patients are referred. Like dyspnea , palpitation can either be a physiological expression of normally beating heart or a dangerous pathological state of the heart. This makes this symptom unique and warrants careful evaluation.
By definition palpitation is abnormal awareness of ones own heart beat. Heart is a mechanical organ with multiple mobile anatomical structures. There is constant blood flow in multiple directions . Apart from this the heart has it’s unique translational, rotational movement . These intrinsic movements combined with proximity to chest wall generate vibratory motion signals .These signals are generally dampened by the encircling pericardial space .The neural signals responsible for perception of palpitation is not clear. If the heart hits against the chest wall it is the somatic nerves from the chest wall that carries the signal. Vibrations generated within the heart chambers, and and the valves are carried by the myocardial and intravascular sensors.( Autonomic) What are causes of palpitation?
Cardiac
- All hyperdynamic circulatory states. It may be generated from either right or left ventricle or both.
- Regurgitant lesions ( Mainly Mitral and aortic regurgitation)
- MVPS*
- Congenital heart disese ( Mainly left to right shunts-ASD/VSD/etc)
- Apart from this patients with prosthetic heart valve, and pacemaker patients can feel their heart beats.
- Cardiac arrhythmia .Both tachycardia, and bradycardia . Ventricular ectopic beats are the very common cause .( It is often described as missed beat)
* Mitral valve prolapse, a very benign condition, over diagnosed in the last few decades raised considerable anxiety and palpitations for the patients (mainly after the diagnosis ! ).Now the cardiology community has sought to underplay this entity with strict diagnostic criteria.( Thickened mitral leaflet ,presence of MR both must be present to label a patient as MVPS)
Non cardiac
- Physiological
- Anxiety state
- Anemia
What is the relationship between ejection fraction and palpitation?
- Generally palpitation indicate a hyper kinetic state of heart .The commonest cause of palpitation is anxiety state .This also happens in hyper dynamic circulations like anemia , fever, thyrotoxicosis, pregnancy etc . In all these situations palpitation indicate increased force of contraction which generates high dp/dt(Rate of rise of ventricular pressure) . So the left ventricularejection fraction is normal or more than normal . So presence of palpitation could be an indirect evidence of reasonably good LV function.
“Patients with dilated cardiomyopathy or CHF rarely feel their heart beat during exertion , instead they have dyspnea as the LV force of contraction is less”
What is the significance of palpitation that occur during rest ?
- Palpitation occurring at rest indicate more often a pathology.It is invariably due to an cardiac arrhytmia either tachycardia or bradycardia. Intelligent patients can give accurate information about the regularity of rhythm , any extra beats or missed beats . Atrial fibrillation, VPDs could be diagnosed by history alone in them !
If palpitation is associated with visible chest pulsation what is the likely diagnosis ?
- If significant visible pulsation over chest wall pulsations are seen in young adults it could simply mean a hyper dynamic circulation and thin chest wall. Pulmonary arterial pulsations is not normally felt in left 2nd inter costal space.If felt one has to rule out shunt lesions like ASD or pulmonary hypertension.
- “ASD is the commonest cause of right ventricular palpitation “
Dr.S.Venkatesan MD 