Pathophysiological mechanisms of onset
The subjective sensation of one's own heartbeat is not always a sign of severe organic pathology, but it is based on clear physiological alterations. There are three main mechanisms that cause the patient to focus on myocardial activity:
- Heart rate (HR) elevation. A conventional rhythm acceleration above normal values makes the patient feel a "fluttering" in the chest.
- Rhythm disturbances (arrhythmias). The omission of a regular contraction, premature beats, or chaotic atrial and ventricular activity is subjectively described as a "thud," "flip-flop," or "heart-stopping" sensation.
- Enhanced myocardial contractility. A critical nuance is that the patient may complain of strong palpitations even with entirely mild tachycardia. This occurs solely due to a sharp increase in the force of cardiac contractions, where each stroke volume forcefully strikes the chest wall.
Anamnesis detailing: questioning algorithm
When taking an anamnesis from a patient presenting with complaints of skipped beats, the physician must strictly follow an algorithm to differentiate functional disorders from life-threatening conditions. Special emphasis during questioning is placed on the paroxysmal nature of the symptoms.
Key points for detailing complaints:
- Time and conditions of onset. It is necessary to determine what preceded the episode (physical exertion, stress, food intake, waking up from sleep).
- Duration of the episode. Sensations may last seconds (as in isolated extrasystoles) or persist for hours.
- Methods of relief. It is important to find out what specifically helps the patient terminate the episode: breath-holding, straining, rest, or taking specific medications.
Pathological etiology of skipped beats
Among the cardiac causes causing subjective discomfort, several main groups of rhythm and conduction disorders are distinguished:
- Extrasystole. The most frequent cause of the sensation of skipped beats ("pauses"). Note that extrasystole is very frequently associated with hypersympathicotonia. Therefore, upon detecting premature contractions, the clinician is obligated to perform a thorough evaluation of the patient's autonomic status.
- Tachyarrhythmias. This group primarily includes conditions such as atrial fibrillation and atrial flutter, in which the heart beats rapidly and irregularly.
- Bradyarrhythmias. The sensation of a "stopped" heart may be associated with a slow rhythm based on various types of impulse conduction blocks.
Remediable (exogenous) factors
Complaints of palpitations do not always indicate actual heart disease. They are frequently provoked by external triggers, the elimination of which leads to the complete resolution of symptoms.
The main exogenous factors include:
- Smoking (toxic effect of nicotine on the autonomic nervous system and myocardium).
- Consumption of caffeine-containing beverages (excessive intake of strong tea or coffee stimulates the sympathoadrenal system).
- Medication intake. A striking example is the use of theophylline-based drugs, which possess pronounced arrhythmogenic and chronotropic potential.
Briefly: answers to topical questions
What specific drug groups, besides theophylline, frequently cause iatrogenic tachycardia and palpitations?
Iatrogenic tachycardia, palpitations, or rhythm disturbances can be provoked by the following medicinal and chemical factors:
- Cardiac glycosides / digitalis preparations — glycoside intoxication is indicated as an iatrogenic cause of atrial paroxysmal tachycardia.
- Antiarrhythmic drugs — possess proarrhythmic effects and are capable of provoking new rhythm disturbances.
- Sympathomimetics — epinephrine is listed among the drug-related factors for sinus tachycardia; ephedrine induces tachycardia.
- Atropine — listed among the drug-related factors for sinus tachycardia.
- Antidepressants and diuretics — listed among iatrogenic medicinal effects associated with arrhythmias.
Additionally, sinus tachycardia can be provoked by caffeine, amphetamines, cannabis, and cocaine.
Which vagal maneuvers help a patient independently terminate an episode of palpitations?
For self-termination of a palpitation episode, the patient is recommended to use specific vagal maneuvers. These include:
- Breath-holding — performed at the maximum deep inspiration.
- Induction of the gag reflex — carried out by pressing on the root of the tongue.
- Valsalva maneuver — breath-holding with a sharp and forceful strain.
- Aschner reflex — pressure applied to the eyeballs.
- Stimulation of the solar plexus — pressing a fist into this area.
- Dive reflex — immersion of the face in cold water.
- Carotid sinus massage — performed strictly on one side only for 15–20 seconds.
What endocrine pathologies are a frequent organic cause of palpitations and tachycardia?
Sources indicate the following as endocrine causes or triggers of palpitations and sinus tachycardia:
- Thyrotoxicosis / hyperthyroidism — accompanied by palpitations and tachycardia; increased excitability, nervousness, sweating, low-grade fever, weight loss despite a good appetite, and muscle weakness are also noted.
- Pheochromocytoma — characterized by paroxysmal arterial hypertension, profuse sweating, palpitations, labile blood pressure, and orthostatic hypotension.
- Cushing's disease.
- Diabetes mellitus — as a cause of sinus tachycardia in the presence of autonomic dysfunction.
What else to study on this topic
- Methods for assessing autonomic status in hypersympathicotonia
- Clinical presentation of atrial fibrillation and atrial flutter
- Types of heart blocks and mechanisms of bradyarrhythmias
- Pharmacodynamics of theophylline and its effect on cardiac rhythm
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