Sinus Tachycardia in Cats
Changes in heart rate usually involve a reciprocal action of the parasympathetic and sympathetic divisions of the autonomic nervous system (i.e., the automatic impulses of the system that control such actions as breathing and heart rate). Sinus tachycardia (ST) is clinically described as a sinus rhythm (heartbeat) with impulses that arise at a faster-than-normal rate: greater than 240 beats per minute in cats.
Severe tachycardia can compromise cardiac output, as too rapid rates shorten the diastolic filling time, the point in which the chambers of the heart dilate and fill with blood -- which occurs in the space between heart beats. Particularly in diseased hearts, the increased heart rate can fail to compensate for decreased volume, resulting in decreased cardiac output, decreased coronary blood flow and a concurrent increase in oxygen demands. This is the most common benign arrhythmia in cats. It is also the most common rhythm disturbance in postoperative patients.
Symptoms and Types
- Often no clinical signs because condition is a compensatory response to a variety of stresses
- If associated with primary cardiac disease, weakness, exercise intolerance, or loss of consciousness may be reported
- Pale mucous membranes if associated with anemia or congestive heart failure
- Fever may be present
- Signs of congestive heart failure, such as shortness of breath, cough, and pale mucous membranes may be present when ST is associated with primary cardiac disease
- Anxiety, anger, fright
- Congestive heart failure
- Chronic lung disease
- Fluid in the chest
- Low oxygen levels/hypoxia
- Pulmonary blood clot
- Low blood pressure
- Reduced blood volume
- Thyroid medications
- Primary cardiac diseases
A medical condition; the contamination of a living thing by a harmful type of bacteria
The prediction of a disease’s outcome in advance
A cavity within a bone; may also indicate a flow or channel
A medical condition in which the patient has an abnormally fast heartbeat
An in-depth examination of the properties of urine; used to determine the presence or absence of illness
Less oxygen than normal in the blood
To make something wider
Not being able to cause harm; the opposite of malignant.
autonomic nervous system
The part of the nervous system that contains the nerves that control involuntary movement.
The amount of pressure applied by the blood on the arteries.
A medical condition in which the body has lost fluid or water in excessive amounts
A condition of the blood in which normal red blood cell counts or hemoglobin are lacking.
A record of the activity of the myocardium