- Sinus bradycardia
SignSymptom infobox
Name = Sinus bradycardia
ICD10 =
ICD9 = ICD9|427.81
MeshID = D001146Sinus
bradycardia is a heart rhythm that originates from the sinus node and has a rate of under 60bpm.Etiology
*This rhythm may be caused by one of the following:
**Increasedvagal tone.
**Intrinsic disease of theSA node .
**An effect ofdrugs , such as the use ofdigitalis ,beta-blockers , or quinidine.
**Sleep
**It could also be a normal finding in a healthy, well-conditioned person.ECG Characteristics
*Rate: Less than 60.
*Rhythm: Regular.
*P waves: Upright, consistent, and normal in morphology and duration.
*P-R Interval: Between 0.12-0.20 seconds in duration.
*QRS Complex: Less than 0.12 seconds in width, and consistent in morphology.ignificance
The decreased heart rate can cause a decreased cardiac output resulting in symptoms such as lightheadedness, dizziness, hypotension, vertigo, and syncope. The slow heart rate may also lead to atrial, junctional, or ventricular ectopic rhythms.
Sinus Bradycardia is not necessarily a bad symptom. People who regularly practice sports may have sinus bradycardia, because their trained hearts can pump enough blood in each contraction.
Sinus Bradycardia can aid in the sport of
Freediving , which includes any of various aquatic activities that share the practice of breath-hold underwater diving. Bradycardia aids in this process due to drop in blood rate pulse. These adaptations enable the human body to endure depth and lack of oxygen far beyond what would be possible without themammalian diving reflex .See also
*
Sinus tachycardia
*Long QT syndrome
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