yogabook / movement physiology / pulse deficit

Pulse deficit

A pulse deficit indicates the number by which a peripheral pulse (e.g. the radial pulse) is reduced compared to the heartbeats, i.e. the difference between heart rate and pulse. Physiologically, there is no pulse deficit. A pulse deficit can occur with

• Severe hypotension, e.g. in shock
• Severe hypertension
• Arterial circulatory disorders, e.g. in the context of PAD
• Arterial thromboses
• Arrhythmias in which hemodynamically ineffective heart contractions occur, e.g. extrasystoles, absolute arrhythmia or atrial fibrillation
• Aortic dissection
• Carotid sinus pressure bandage

A pulse deficit can be divided into complete and incomplete,
Complete is when a ventricular contraction does not pump any blood.
Typically, a pulse deficit decreases when the head is lowered to heart level, as when lying down, and increases again when the head is raised. Furthermore, the pulse deficit often decreases as blood pressure rises. Even minor physical activity significantly reduces the pulse deficit, and light exertion such as climbing stairs often causes it to disappear. A pulse deficit can be a sign of heart failure. In 50% of patients with pulse deficits, there are no symptoms; in the other half, palpitations, reduced performance or even presyncopes are noticed.

Because extrasystoles can also trigger a pulse deficit, their causes, some of which are harmless, must also be considered as indirect causes. Supraventricular extrasystoles (SVES, atrial extrasystoles), which occur in the atrium (atrial SVES) or in the AV node (nodal SVES), are usually asymptomatic because they affect hemodynamics less than ventricular extrasystoles (VES). They only occasionally cause heart stumbling or palpitations. In rare cases, dizziness may also occur,
anxiety, nervousness or fainting. They are often found incidentally on the ECG and do not require treatment in otherwise healthy people. Ventricular extrasystoles (VES) can always look the same on the ECG (monomorphic) and are not always pathological, or they often appear differently (polymorphic) and indicate myocardial damage. If a regular heartbeat is followed by only one extrasystole, this is referred to as a bigeminal beat, a trigeminal beat is followed by two extrasystoles and more than two are referred to as volleys. If the extrasystole is too close in time (within the refractory period) to a regular cardiac action, the latter cannot be hemodynamically effective and a compensatory pause occurs. This has no pathological value, but can be perceived as a heart stumble.

Sport is one of the harmless causes of extrasystoles, which also occur in healthy people. They can occur during exercise because the relative lack of oxygen favors potential fluctuations in the heart muscle cells, i.e. affects the electrochemistry of the heart. Due to the adrenergic situation and depending on its extent, dromotropy (excitation conduction) and bathmotropy (excitability) are promoted, the latter above all favoring extrasystoles. This is harmless in otherwise heart-healthy people. Extrasystoles can also occur after sport, because the increasingly active vagus nerve has an increasing influence on the heart when the sympathetic nervous system is simultaneously declining. In addition to sport, stress can also promote extrasystoles in various ways due to the increased excitation of the body, which applies to both dystress and eustress. This is particularly pronounced in the case of cardiac neuroses.

Pregnancy can also promote extrasystoles, especially at the beginning and towards the end. This indicates that thyroid values, electrolytes and cardiac activity should be monitored by ECG. Toxins such as nicotine and caffeine, but also alcohol (consumption and withdrawal) can also lead to extrasystoles. Among the electrolytes, potassium, magnesium (deficiency) and calcium imbalances are particularly conducive to extrasystoles.