N-Terminal Pro-B-Type Natriuretic Peptide and Phonocardiography in Differentiating Innocent Cardiac Murmurs from Congenital Cardiac Anomalies in Asymptomatic Puppies.

BACKGROUND: Differentiating innocent cardiac murmurs from murmurs caused by congenital cardiac anomalies can be challenging with auscultation alone in asymptomatic puppies. HYPOTHESIS: Plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations and phonocardiograms recorded by an electronic stethoscope can differentiate innocent from pathologic cardiac murmurs. ANIMALS: A total of 186 client-owned asymptomatic dogs: 135 Cairn Terriers (age: 45-124 days), 20 adult Cairn Terriers (age: 7.5 months to 13.5 years), and 31 puppies of various breeds (age: 29-396 days). METHODS: Study design is a cross-sectional survey. Each dog was auscultated, and when a cardiac murmur was heard, a phonocardiogram was recorded and an echocardiogram was performed. Plasma NT-proBNP concentrations were measured by a single laboratory by an ELISA. RESULTS: No significant (P = .41) difference in plasma NT-proBNP levels was found between puppies without a murmur and puppies with an innocent murmur (median 300 versus 326 pmol/L), and between clinically healthy adult Cairn Terriers and Cairn Terrier puppies. Plasma NT-proBNP levels in puppies with a congenital heart disease were significantly (P < .001) higher than those in puppies with innocent murmurs (median 1,102 versus 326 pmol/L). However, some puppies with severe pulmonic stenosis did not have increased plasma NT-proBNP levels. On phonocardiograms, innocent murmurs had a significantly (P < .001) shorter "murmur-to-systole duration ratio" than the abnormal ones (median 66 versus 100%). The "murmur-to-S1 (first cardiac sound) amplitude ratio" was significantly (P < .001) lower of the innocent murmurs compared with that of the abnormal ones (median 16 versus 58 %). CONCLUSIONS AND CLINICAL IMPORTANCE: Plasma NT-proBNP concentrations within the reference range do not rule out a congenital cardiac anomaly. Murmurs longer than 80% of the systole are most likely abnormal, whereas murmurs shorter than that could be either innocent or pathologic.

Innocent Cardiac Murmur in Puppies: Prevalence, Correlation with Hematocrit, and Auscultation Characteristics.

BACKGROUND: The aims of this study were to establish the prevalence of innocent cardiac murmurs in clinically healthy puppies, to investigate a possible correlation between the presence of an innocent murmur and hematocrit, and to describe the auscultation characteristics of innocent murmurs. HYPOTHESIS: Lower hematocrit contributes to the genesis of innocent murmurs. ANIMALS: Five hundred and eighty-four client-owned clinically healthy puppies, between 20 and 108 days old. METHODS: Two cross-sectional surveys with a 1-year (n = 389 pups) pilot and a half-year (n = 195 pups) principal study periods. Cardiac auscultation was performed by a single, board-certified cardiologist. Hematocrit was measured with an automatized hematology analyzer. Echocardiography was performed only on puppies with a cardiac murmur in the principal study. RESULTS: In the pilot study, 15% of the dogs had a murmur. Innocent murmur was diagnosed in 28% of the 195 dogs in the principal study. Innocent murmurs were systolic, mostly with a musical character and with a maximal intensity of 2 of 6, and mostly with the point of maximal intensity in the left cardiac base. The hematocrit was significantly lower in the group with a murmur compared to the group without (P = .023). CONCLUSIONS AND CLINICAL IMPORTANCE: Innocent murmur was a common finding in puppies at the age when the first veterinary controls usually take place. Physiologic anemia contributes to the genesis of innocent murmurs in puppies. Rising hematocrit in growing puppies can explain the spontaneous disappearance of innocent murmurs with aging. Hematocrit did not differentiate innocent murmurs from abnormal murmurs.

Heart murmur and anaemia in the pediatric population.

Innocent heart murmurs are hearth murmurs that occur in patients with a normal heart structure. They do not represent a disease of the heart and vascular system, and should not be treated as such. Iron-deficiency anaemia often causes, along with other symptoms, systolic heart murmurs and tachycardia. It appears in children of all ages representing a most common haematological paediatric disease. To establish the influence of iron-deficiency anaemia on genesis of innocent murmurs and to compare auscultatory and phono-electrocardiographic findings in patients with anaemia and heart murmurs before and after iron therapy. The study includes 120 patients with innocent heart murmurs that have been auscultated at cardio-rheumatic outpatient department of Pediatric Clinic of the Clinical Center of the University of Sarajevo, during the period from 01/01/2004 to 31/12/2004. Further diagnostic procedure, i.e. laboratory tests, diagnosed iron-deficiency anaemia in 30/120 patients. These patients have been followed in this study. 22/30 patients had systolic murmur I/II intensity of Levin scale; 8/30 patients had II/VI systolic murmurs of intensity by Levin. The highest number of examinees had 0-1 years of age, and in this group the number of boys was higher than the number of girls (M: F = 12:4). During the auscultatory and phono-ECG examinations of murmurs, 6 patients had haemoglobin values less than 95 g/l, which corresponds to an average and severe type of anaemia. 24 patients had haemoglobin values between 95 and 110 g/l, which corresponds to benign type of anaemia. The most numerous were patients aged between 0 - 1 year (3 patients with hemoglobin value Hb < 95 g/l, 13 patients with hemoglobin value Hb 95-110 g/l). All patients were treated with iron medicaments. After three months, clinical and laboratory re-evaluation was performed and it has demonstrated that after iron therapy 24 patients had level of a haemoglobin Hb >110 g/l and 6 patients had haemoglobin levels between 95 and 110 g/l. By auscultatory and phono-ECG examinations, murmurs of a level of intensity I/II was registered in only one child, while in the other 29 patients there were not any registered heart murmurs. Diagnosis of anaemia in the paediatric population group delays definitive diagnosis of heart murmurs. Innocent murmurs in children with sideropenic anaemia occur as its consequence. After adequately conducted iron therapy, i.e. cured anaemia, heart murmurs were not auscultated.