Changes

===Echocardiography===

===Echocardiography===

In dogs, echocardiography is not particularly useful as a diagnostic tool for heartworm disease. In severe, chronic pulmonary hypertansion, right ventricular hypertrophy, septal flattening, underloading of the left heart, and high-velocity tricuspid and pulmonic regurgitation may be seen¹. With caval syndrome or high-burden infections, worms may be visualised in the right heart and vena cava.

In dogs, echocardiography is not particularly useful as a diagnostic tool for heartworm disease. In severe, chronic pulmonary hypertension, right ventricular hypertrophy, septal flattening, underloading of the left heart, and high-velocity tricuspid and pulmonic regurgitation may be seen¹. With caval syndrome or high-burden infections, worms may be visualised in the right heart and vena cava.

Echocardiography is more important in cats than dogs because of the increased difficulty of diagnosis and the fact that this test can have a high sensitivity depending on operater experience¹. Specificity is 100%⁵, and the test can help exclude or confirm other primary cardiac diseases such as hypertrophic cardiomyopathy³. Worms can usually be visualised as parallel hyperechoic lines¹, and are seen in the right atrium and ventricle and main pulmonary artery^{1, 3, 5}.

Echocardiography is more important in cats than dogs because of the increased difficulty of diagnosis and the fact that this test can have a high sensitivity depending on operater experience¹. Specificity is 100%⁵, and the test can help exclude or confirm other primary cardiac diseases such as hypertrophic cardiomyopathy³. Worms can be visualised as parallel hyperechoic lines¹, and are seen in the right atrium and ventricle and main pulmonary artery^{1, 3, 5}.

===Electrocardiography===

===Electrocardiography===