Health library emergency diseases a-z pet care topic center veterinary terms news alerts & recalls care & safety health & science lifestyle petlanthropy strange but true breeds dog cat horse adoptable dogs adoptable cats compare dog breeds compare cat breeds compare horse breeds centers service finder slideshowsnew blue buffalo centernew nutrition raw dietnew puppy kittennew litternew living green parasite pet insurance bird care blogs fully vetted the daily vet purely puppynew nutrition nuggetsnew healthy assurance ask a vet symptom checker pet360 q&a follow us login | register connect select your animal: mange in dogs parvo in dogs chocolate poisoning in dogs lyme disease in dogs acute vomiting in dogs common searches: ask a vet | symptom checker | slideshows home â» dog conditions x close alert nature's deli chicken dog treats recalled read article irregular heartbeat in dogs share | print sinus arrhythmia in dogs   arrhythmia is caused by an abnormal variation in the cycling of impulses that regulate the heart's beating action, resulting in an irregular rhythm. The heart may beat too fast, too slow, or it may skip beats. cheap viagra online An irregular heart beat is the primary symptom of arrhythmia. free samples for viagra   the sinoatrial node (sa node, or san), also called the sinus node, is the initiator of electrical impulses within the heart, triggering the heart to beat, or contract, by firing off electrical surges (also called the heart's pacemaker). The sinus discharge rate depends on two opposing influences of the nervous system: stimulation from the vagus nerves (nerves that originate in the lower brain stem [medulla] and send signals to the autonomic organs of the body) decreases the spontaneous discharge rate and predominates over sympathetic stimulation (mediating the neuronal and hormonal stress response commonly known as the fight-or-flight response). During inhalation, feedback from the respiratory and cardiac centers produce cardiac acceleration by decreasing restraints on the vagus nerves; the opposite occurs during exhalation. alcohol effects on viagra   sinus arrhythmia also depends on reflexes involving stretch receptors in the lung, pressure-volume sensory receptors in the heart, blood vessels, and chemical factors of the blood. viagra online There is generally no consequence in blood flow, but marked sinus arrhythmia may produce a long enough pause in the heart's beating action to produce loss of consciousness if not accompanied by an escape rhythm. viagra jelly canada   arrhythmia is relatively common in d. viagra