Spectral analyses of avian heart value sounds

Abstract

Cardiovascular changes which occur in response to cardiac stress affect the heart valve sounds (HVS). We attempted to quantify the effect of pulmonary hypertension and right ventricular (RV) hypertrophy on the frequency spectrum of HVS. A test group of broiler chicken were exposed to low temperatures (100C) from one to four weeks of age; a control group was exposed to normal temperatures (25'C) for the same period. Low temperatures were used to induce ascites syndrome (ASC), a condition causing pulmonary hypertension and RV hypertrophy in broilers. The HVS and the electrocardiogram (ECG) were recorded every week for four weeks. The HVS was transformed into the frequency domain in order to obtain the HVS spectrum. Characterizing parameters were extracted from the HVS spectrum. At the end of four weeks, all broilers were necropsied and those afflicted with ASC were identified. Statistical analysis was performed on the data obtained every week to check for differences in the parameters between the healthy and the afflicted broilers. Differences were detected as early as one week in some of the parameters extracted from the heart valve sound spectra. Differences in the parameters extracted from the electrocardiogram were detected at the third and fourth week.