Palpitations are the conscious and annoying sensation of cardiac action.
Even though they are one of the frequent manifestations that lead the patient to the medical consultation, they are the most nonspecific of the symptomatic set. However, its exact semiological knowledge is of great diagnostic importance and can often guide the underlying pathology.
They are, as stated, the conscious sensation of the heartbeat; therefore, they represent a functional and eminently subjective symptom, and their intensity intervenes, to a large extent, the threshold of sensitivity of each person. The perception or awareness of a physiological phenomenon, in this case the heartbeat, always causes an annoying sensation that can vary from discomfort to pain according to the intensity of perception. The reason that a physiological fact, the heartbeat, becomes conscious would only be due to a decrease in the perception threshold, or hypersensitivity, related to the psychology of each individual. Under normal conditions, there are also moments of cardiac hyperactivity, with tachycardia and increased return venous flow, that promote the perception of the heartbeat and that appear in the postprandial periods, as a result of emotions and anxiety neurosis, during and after exercise, or when waking up or starting sleep. Palpitations of this type are called physiological and have no clinical significance. They are often accompanied by a transient shortness of breath, forcing you to take a deep breath, called breathless breathlessness.
In palpitations, the heartbeat is perceived, which can occur in a diseased heart or not, a fact that, in the latter case, is purely functional and would originate in any alteration of the organism that occurs with tachycardia, dysrhythmia or bradycardia.
This symptom is known by means of the patient's questioning and, in order for its analysis to acquire value, it is necessary to have a clear idea of the forms of presentation in order to draw correct diagnostic conclusions.
Palpitations have three types of presentation: 1) continuous, 2) discontinuous or extra-systolic, and 3) paroxysmal.
Continuous type . They are those that present with a feeling of a strong and annoying heartbeat, with a perception of a moderate increase in heart rate or not. The variety of continuous and strong beat appears in two different circumstances: at rest or by effort.
The first of the possibilities of a continuous and strong heartbeat at rest occurs when it is accompanied by a sensation of moderate cardiac acceleration, such as in anorganic (neurosis, neurovegetative dystonia) or organic extra-cardiac symptoms (including hyperthyroidism, fever, anemia). Cardiopathic patients can also cause this type of effort palpitations; as a sign of heart failure. In these cases they are accompanied by dyspnea.
If the sensation is continuous and strong at rest, but there is no perception of increased heart rate, its etiology may be an organic condition of the heart. There are two main causes: one is cardiac enlargement of any origin and the other is aortic insufficiency.
Cardiomegaly, by bringing the heart closer to the costal wall, favors the perception of its actions, especially in the physiological moments in which its work is increased and in positions such as left decubitus.
Aortic insufficiency, by dilating the left ventricle and bringing it closer to the costal wall, predisposes to the clear perception of its action because the increased differential pressure induces ventricular hyperdynamia. It is necessary to know that this pathology generates palpitations with a throbbing sensation in the neck, due to the perception of the arterial dance existing in it. This is a very significant piece of aortic regurgitation. Of course, by increasing the heart rate, for example, due to exercise or an emotion, palpitations are exaggerated.
Continuous palpitations generate a stronger than fast heartbeat sensation, and this is its main characteristic.
Discontinuous or extra-systolic type . It is a sensation of palpitation in an instant, followed by normal work that the patient does not perceive, and that configures a discontinuous perception. It presents as a unique sensation of palpitation that is not repeated for a long period of time and forms an isolated discontinuous palpitation variety; but it can also be sensations that are repeated more often in short periods, and that appear as more frequent discontinuous palpitations.
The origin of this type of palpitations is an extra systolic dysrhythmia. They are caused by premature contractions, or extrasystoles, both supraventricular and ventricular.
The perceived sensation can be variable, and it is noted as a strong throbbing in the chest or a feeling of constriction in the throat, or as a bubble that rises to the neck. Other times, if the perception is intense, it can generate a sensation of pain, precordial stitch or painful epigastric beat. Some patients only notice the momentary absence of the heartbeat and a need to breathe deeply.
Discontinuous palpitation due to extrasystole sometimes originates in the premature beat, while in others the two or three post-extra-systolic beats are perceived, which begin with a more intense one caused by the greater diastolic filling immediately after the extrasystole.
Paroxysmal type . The palpitations that appear at any time, unrelated to any contributing factor, generate a sensation of a very fast heartbeat, which is perceived as faster than strong, and it is not the increase in intensity of the beat that causes them, but the acceleration cardiac.
They can be perceived as a feeling of rapid and equal or regular beats or, on the contrary, as fast and irregular. This data is very important, because it adequately guides the dysrhythmia that generates them. The type described corresponds to paroxysmal dysrhythmic attacks.
Regular paroxysmal palpitations are associated with paroxysmal supraventricular or ventricular tachycardia and atrial flutter with regular ventricular frequency, as well as ventricular flutter.
The irregular paroxysmal variety appears in atrial fibrillation aond atrial flutter with variable ventricular rate.
Its duration can be seconds, minutes, hours or even days and, in general, they are accompanied by precordial pain and dyspnea; the faster the heart rate or the worse the condition of the underlying myocardium, the more likely it is that hypotension, transpiration, oliguria and dizziness will appear due to shock or peripheral circulatory failure.
Most frequent causes of palpitations
Neurocirculatory asthenia . Palpitations are one of the most characteristic symptoms of this condition, which was described at the end of the last century during different wars and is also known as cardiac neurosis or soldier's heart. It appears to be due to an imbalance of the autonomic nervous system in constitutionally frail people. The heart, in most cases, is structurally normal. Many patients with this condition are diagnosed today as having a prolapse of the nitral valve.
Mitral valve prolapse . It is found in 10-20% of the general population. Pcharacterized by a prolapse of the mitral valve into the left atrium during ventricular systole, due to laxity of the valve tendon cords. The phenomenon can also occur in the tricuspid valve. A physical proto, meso, or end-systolic (most often mesosystolic) click is found on physical examination, disappearing with changes in position, and a end-systolic murmur. The diagnosis is confirmed by echocardiography. It can be accompanied by different atrial and ventricular arrhythmias and is the most common cause of palpitations in the doctor's office.
Classification of arrhythmias.
Regular. They can be fast, normal or slow frequency. Rapid rates, above 100 per minute, include sinus tachycardia, supraventricular (atrial or nodal) tachycardias, atrial flutter with a regular ventricular response, and ventricular tachycardia. Those of normal frequency, between 60 and 100, are normal sinus rhythm and atrial flutter with normal ventricular response. Those with a low frequency, below ñ60, are sinus bradycardia and complete and second degree heart blocks.
Irregular. The irregularity can be rhythmic or sporadic, including sinus arrhythmia and atrial extrasystoles, of the atrio-ventricular or ventricular junction. It can also be total, as in atrial fibrillation and atrial flutter with varying degrees of blockage.