Page 59 - Feline Cardiology

54 Section B: Diagnostic Testing

Diagnostic Testing AO

A

AO

Figure 7.2. The color-flow Doppler echocardiograms obtained
B at the right parasternal window. The pulmonary artery is being
interrogated with color-flow Doppler. (A) Right ventricular outflow
is labeled in blue because the blood is exiting the heart away from
the transducer. Note: the color-flow Doppler scale (upper corner
of each frame) is set so that flow velocities of up to 104 cm/sec
can be measured before aliasing will occur. (B) In this frame, note
that the color-flow Doppler scale has been reduced to 65 cm/s and
AO
the pulmonary flow pattern shows “color reversal” (both yellow
and blue labeling are displayed because the flow velocity is above
the range of the current scale, so aliasing occurs). (C) “Color re-
versal” is also noted in this patient’s pulmonary artery; however,
the color-flow Doppler scale is set at 104 cm/s. When the region
is evaluated using continuous-flow Doppler (which can measure
high velocity flows), this cat was found to have accelerated pul-
monary artery outflow consistent with mild pulmonic stenosis
C
(300 cm/s). Ao = aorta.

will change the immediate treatment plan for a cat Ideally, the patient will be tractable for the examina-
in heart failure, and therefore reserving the complete tion without sedation. However, if the patient is uncoop-
echocardiogram until after therapy and stabilization of erative, mild sedation may be necessary. The following
the patient in distress is critical. Some echocardiogra- combinations are less likely to affect echocardiographic
phers prefer imaging animals in a standing position, but results than general anesthesia (see Chapter 27 for more
restraint is often more difficult. Usually plentiful use of information):
isopropyl rubbing alcohol and acoustic gel on the
patient’s skin will result in good acoustic contact and • Light sedation
optimizes image quality. However, occasionally the hair • Low-dose acepromazine (0.11–0.22 mg/kg IM or
of obese or long-haired cats will need to be clipped for SQ) and an opiate (e.g., buprenorphine (0.005–
optimal image acquisition. 0.01 mg/kg IV or IM), or