Analysis of murmur intensity, duration and frequency components in dogs with aortic stenosis.

A study was undertaken to investigate the relationship between murmur intensity, murmur duration, duration to peak intensity and frequency components with degree of aortic stenosis in boxers. Measurements were made from phonocardiograms obtained from 35 boxers with ejection-type murmurs, and values were compared with those obtained for aortic flow velocity measured by Doppler echocardiography. Murmur intensity graded by auscultation was significantly correlated with aortic flow velocity (P < 0.001), and murmur duration, expressed as a percentage of systole was significantly correlated with aortic flow velocity (P < 0.001), independent of heart rate. Dogs with early systolic murmurs not exceeding 50 per cent of systole had aortic flow velocities of less than 1.5 m/second and no echocardiographic abnormalities, in contrast with dogs with murmurs of longer duration. Dogs with only high frequency components had lower aortic velocities than those that also had components in the medium frequency range (P < 0.01).

Pulmonary venous flow characteristics as assessed by transthoracic pulsed Doppler echocardiography in normal dogs.

Transthoracic Doppler echocardiography was used to evaluate the technique of measuring and normal patterns of pulmonary venous flow in fourteen normal dogs. Polyphasic pulmonary venous flow profiles were obtained in all dogs, consisting of one (S) or two (SE and SL) systolic forward flow waves, one early diastolic forward flow wave (D), one reverse flow wave (R) related to atrial contraction, and one reverse flow wave (R2) observed after cessation of systolic flow. Pulmonary venous flow was laminar in 9 dogs (65%). Maximal flow velocity during systole (0.39 +/- 0.14 m/sec) was significantly lower (P < 0.01) than in early diastole (0.56 +/- 0.14 m/sec). During late diastole peak flow velocity was 0.20 +/- 0.08 m/sec and maximum R2 velocity was 0.17 +/- 0.05 m/sec. Duration of mitral A-wave was significantly greater (P < 0.05) than R-wave duration in all dogs (0.075 +/- 0.010 vs 0.058 +/- 0.012 sec). These results can be used for comparison with patterns found in disease states.

Measurement of cyclic variation in ultrasonic integrated backscatter in conscious, unsedated, clinically normal dogs.

OBJECTIVE: To assess the feasibility and repeatability of measuring ultrasonic integrated backscatter in unsedated conscious dogs, using a protocol previously validated in pigs with open thorax. ANIMALS: 11 clinically normal conscious unsedated German Shorthair Pointers. PROCEDURE: A modified commercially available echocardiography system was used to record long-axis views of the heart. The radiofrequency data from 15 consecutive frames were digitized and analyzed. Regions of interest were chosen within the myocardium, and the ultrasonic integrated backscatter within each region was calculated in the time domain for each frame. RESULTS: Cyclic variation in integrated backscatter values was observed, with maximal values at end-diastole and minimal values at end-systole. Mean +/-SD amplitude of cyclic variation was 5.81 +/- 3.86 dB over all the regions chosen. CONCLUSIONS: Results agreed with those obtained by other investigators working with dogs with open thorax and those with closed thorax while under general anesthesia. The analysis of the components of variance indicates that this is a consistent, reliable technique in conscious unsedated dogs. CLINICAL RELEVANCE: Integrated ultrasonic backscatter measurement provides a noninvasive means of tissue characterization. Use of this protocol reliably yields cyclic variation in integrated backscatter and could be applied clinically to dogs with myocardial disease.

Thoracic spinal calcinosis circumscripta causing cord compression in two German shepherd dog littermates.

Two young German shepherd dog littermates had progressive, painless, hindlimb ataxia. In both dogs plain radiography of the vertebral column revealed a solitary mineralised lesion on the dorsal laminae between the dorsal spines of the second and third thoracic vertebrae, and myelography with iopamidol demonstrated cord compression at the level of the lesions. The first dog died 18 hours after the myelography. A dorsal laminectomy performed in the second dog resulted in neurological improvement. A histopathological examination confirmed that both lesions were calcinosis circumscripta. The cause of the death of the first dog was meningitis.

Detection, localization, and treatment of occult bronchogenic carcinoma in nickel workers.

Asymptomatic men exposed to nickel sulfide prior to 1963 were studied prospectively to investigate cytologic abnormalities in the sputum. We discovered a considerably greater incidence of squamous cell tumors that would have been expected from subjects exposed only to cigarette smoke.