Vet Articles & Papers
Ventricular rhythms that are faster than ventricular escape, but slower than classical ventricular tachycardia are termed accelerated ventricular rhythms. Most ventricular escape rhythms have an inherent heart rate of 20-45 beats-per-minute (bpm) in the dog. Ventricular tachycardia is present if the rhythm is ventricular and the heart rate is arbitrarily over 180 bpm. Everything in between (heart rate 45-180 bpm) is considered to be accelerated, and usually the result of increased normal or abnormal automaticity occurring in the Purkinje fibers of origin. This may be the result of ischemia with subsequent reperfusion, hypoxia, electrolyte abnormalities as well as drugs (digitalis […]
Introduction: Pulmonary hypertension (PHT, pulmonary arterial hypertension or PAH) is a condition in which the blood pressure in the lungs is excessively elevated. The normal blood pressure in the pulmonary artery (PA) is no more than 30 mmHg systolic and 19 mmHg diastolic. Patients with severe PHT may have systolic pulmonary arterial pressures greater than 80 mmHg. Pulmonary hypertension is an important rule-out in patients presenting to the clinician with dyspnea, cyanosis and/or syncope, especially if appropriate medical therapy for any underlying heart and lung disease is failing to significantly improve symptoms. Pulmonary hypertension is most often diagnosed in small […]
Syncope (fainting) is defined as a sudden and transient loss of consciousness due to deprivation of the brain of energy substrate, be it oxygen or glucose, causing brief impairment of cerebral metabolism. The brain’s energy supply is limited to glucose as provided from cerebral blood flow. Presyncope occurs when the animal does not experience a complete loss of consciousness. The causes of syncope are manifold and often elude accurate diagnosis. Furthermore, it can be exceedingly difficult to differentiate syncope from neurologic seizure in veterinary patients. Clinical signs in humans typically entail “lightheadedness,” vertigo and falling over with flaccid, brief paralysis. […]
Introduction: Cardiomyopathy in cats comprises an incompletely understood group of diseases. The term cardiomyopathy means heart muscle disease, and encompasses multiple phenotypic variants. The most common and extensively studied type that is diagnosed in cats is hypertrophic cardiomyopathy (HCM), and is not the focus of this discussion. The other cardiomyopathies include dilated cardiomyopathy, restrictive cardiomyopathy, and unclassified or ischemic cardiomyopathy. Subcategories of these include moderator-band associated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy and left ventricular non-compaction. It is unclear what role myocarditis/endomyocarditis (inflammation of the heart muscle) plays in the development and/or exacerbation of cardiomyopathy in cats. Future studies may help […]
