After puberty, the average male pulse rate is slightly lower than the female.
The pulse rate normally increases with activity. Short-term exercise can increase pulse rate. Long-term exercise conditions the heart，resulting in lower rate at rest and quicker return to resting level.
In response to stress, sympathetic nervous stimulation increases the overall activity of the heart. Stress increases the rate as well as the force of the heartbeat. Fear and anxiety as well as the perception of severe pain stimulate the sympathetic system.
When a person assumes a sitting or standing position, blood usually pools in dependent vessels of the venous system. Pooling results in a transient decrease in the venous blood returning to the heart and subsequent reduction in blood pressure and increase in heart rate. Pulse rate decreases when client is lying down.
Atropine can increase heart rate. Digitalis can decrease the heart rate.
Loss of blood increases pulse rate.
Fever can cause an increased pulse rate. Decreased pulse rate is often seen with hypothermia.
Character of the Pulse and Observation of Abnormal Pulse
When assessing the pulse, the nurse must consider the variety of factors influencing pulse rate．A combination of these factors may cause significant changes．If the nurse detects an abnormal rate while palpating a peripheral pulse，the next step is to assess the heart rate．The heart rate provides a more accurate assessment of cardiac contraction．
Two common abnormalities in pulse rate are tachycardia and bradycardia．
Tachycardia is an abnormally elevated heart rate，above 100 beats per minute in quiet adults． It is seen in the clients with fever, anemia, hemorrhage and hyperthyroidism.
Bradycardia is a slow rate, below 60 beats per minute in quiet adults．It is seen in the clients with atrioventricular block, increased intracranial pressure, and hypothyroidism.
Normally a regular interval of time occurs between each pulse or heart beat．An interval interrupted by an early or late beat or a missed beat indicates an abnormal rhythm or dysrhythmia．
Intermittent Pulse is also called premature beat. It means one pulse missing during regular or irregular pulse patterns, in which the rhythm is irregular and uneven. It can be called bigeminy or trigeminy if one pulse absents every one or two normal pulses. This can be seen in cardiomyopathy, myocardial infarction, digitalis intoxication, and transient symptoms caused by excited emotion or fear. Intermittent pulse threatens the heart ability to provide adequate cardiac output, particularly if it occurs repetitively. The nurse identifies an intermittent pulse by palpating an interruption in successive pulse waves or auscultating an interruption between heart sounds. An electrocardiogram (ECG) is necessary to define the pulse dysrhythmia.
Children often have a sinus dysrhythmia, which is an irregular heartbeat that speeds up with inspiration and slows down with expiration. This is a normal finding and can be verified by having the child hold his or her breath; the heart rate should then become regular.
The pulse deficit is that pulse rate is less than heart rate. An inefficient contraction of the heart that fails to transmit a pulse wave to the peripheral pulse site creates a pulse deficit．Pulse deficits are frequently associated with dysrhythmias．It can be seen in clients with atrial fibrillation. To assess a pulse deficit the nurse and a colleague assess radial and apical rates simultaneously and then compare rates．
The strength or amplitude of a pulse reflects the volume of blood ejected against the arterial wall with each heart contraction and the condition of the arterial vascular system leading to the pulse site．Normally the pulse strength remains the same with each heartbeat．Pulse strength may be graded or described as strong, weak, thready, or bounding．It is included during assessment of the vascular system．
Bounding pulse denotes an increased stroke volume, which can be palpated by fingertips slightly. It is often seen with fever, hyperthyroidism, and aortic incompetence.
The pulse is weak and diminished, which is barely palpated by fingertips. It often occurs with massive hemorrhage, shock, and aortic stenosis.
The pulse alternates between increased and diminished patterns along with strong and weak contraction of the ventricles. Common causes are hypertensive heart disease, myocardial infarction.
The abrupt distension and quick collapse of the pulse is palpated following the increased cardiac output with resultant pulse pressure surges. It often occurs with hyperthyroidism, aortic incompetence.
A pulse marked by a double beat, with the second beat weaker than the first. It can be an indication of dilated cardiomyopathy.It has a systole peak and a diastole peak (in contrast to pulsus bisferiens, which has two peaks in systole.)
The pulse is obviously weak or not palpable on inspiration. It results from the declined strokes by the left ventricle on inspiration. Common causes are pericardial effusion and constrictive pericarditis.