Special Examination of Cardiovascular System Cardiovascular system comprises heart, arteries, veins, blood cells and plasma. Of them two functional units are heart and blood vessels. Any affection of these functional units precipitates as various clinical manifestation. In order to get a confirmatory diagnosis various clinical examinations are being performed. The various clinical examinations of cardiovascular system are as followed. 1. History and physical examination 2. Electrocardiography (ECG) 3. X- radiography 4. Echocardiography 5. Cardiac biomarkers History: A good history and physical examination are invaluable in making a diagnosis of heart disease and helping to differentiate heart disease from pulmonary disease. Besides helping to make the diagnosis, a good history and physical examination help to tell the extent of the problem, the animal’s response to previous therapy, the owner’s ability to medicate the animal consistently, and the presence of other medical problems. History includes signalments and specific sympotms. Signalment: Age: Young animals usually have congenital diseases (e.g., patent ductus arteriosus [PDA]), whereas older animals usually have acquired diseases, such as degenerative diseases (e.g., mitral and tricuspid regurgitations) or neoplastic diseases (e.g., heart base tumor). Breed: Certain cardiac defects are more common in some breeds of animals; however, there can be regional differences in the rate of occurrence of cardiac problems. Breed Common Cardiac Problems Boxer ARVC (arrhythmogenic right ventricular cardiomyopathy) Doberman Pinscher DCM (dilated cardiomyopathy) Sex: Males are more susceptible to certain cardiac diseases (e.g., male Cocker Spaniels to chronic valvular heart disease of the mitral valve and large breed males to dilated cardiomyopathy). However, sick sinus syndrome occurs in the female Miniature Schnauzer, and PDA is more common in females of small breed dogs.
Utilization of the animal: Knowing how an animal is going to be used when giving a long-term prognosis for a cardiac disease is important. For example, hunting dogs with severe heartworm disease may not be able to hunt again after treatment. Also, some animals with congenital heart defects may have normal life spans and may make good pets; however, they should not be used for breeding purposes because the defect could be perpetuated. The age, breed, and sex of the animal may help the clinician to make an accurate diagnosis; however, there are always exceptions to every rule. Specific Symptoms: Various clinical manifestations attributed to cardiovascular disorders are as followsCoughing: A cardiac cough caused by left-sided heart failure occurs only when the pulmonary edema is peracute and severe enough that fluid accumulates in the airways. This cough is soft and moist sounding and produces blood-tinged Sputum. Dyspnea: Dyspnea is difficult, labored, or painful breathing. It is usually preceded by tachypnea (an increased rate of breathing), which owners may miss. Hemoptysis: Cardiac causes of hemoptysis include severe pulmonary edema (e.g., ruptured chordae tendineae) and severe heartworm disease, usually with pulmonary embolism. Syncope: Syncope is a loss of consciousness caused by inadequate cerebral blood flow. It can recur and is usually brief. Causes of syncope in case of dog and cats: Disease with poor cardiac output (e.g., dilated cardiomyopathy) Severe bradycardia (e.g., complete heart block, sick sinus syndrome) Severe sustained tachycardias (e.g., atrial or ventricular tachycardia) Severe hypertrophic cardiomyopathy in cats Weakness and Exercise Intolerance: Weakness and exercise intolerance are nonspecific signs of heart disease. Many diseases such as severe anemia, systemic diseases, metabolic diseases (e.g., hyperadrenocorticism), drug toxicities, and severe respiratory diseases can cause these signs. Ascites: Ascites is an accumulation of fluid in the abdomen. Ascites caused by cardiac problems is caused by either the inability of the right side of the heart to pump the blood presented to it or to pericardial disease, which prevents the blood from entering the right side of the heart. Cyanosis: Cyanosis is blue-tinged mucous membranes of the gums, tongue, eyes, ears, and other areas and is associated most commonly with right-to left shunting congenital heart defects. Weight Loss: Weight loss occurs in dogs with chronic, severe right-sided heart failure (e.g., severe tricuspid regurgitation, dilated cardiomyopathy, advanced heartworm disease). Paresis: Cats with acute posterior paresis or paresis of one front leg often have thromboembolism resulting from cardiomyopathy. Physical Examination : It includes Palpation, Percussion and Auscultation. Auscultation of heart is one of the most important physical examination of cardiovascular system.
Fig. Areas of auscultation in the dog. M is the mitral valve area, A is the aortic valve area, P is the pulmonic valve area, and T is the tricuspid valve area. Area of auscultation in dog and cat: Structure Location Mitral valve (left apex) Dog—left side, fifth intercostal space at costochondral junction Cat—left side, fifth to sixth intercostal space near sternum Aortic valve (left base) Dog—left side, fourth intercostal space just above costochondral junction Cat—left side, second to third intercostal space just dorsal to pulmonic area Pulmonic valve (left base) Dog—left side, between second and fourth intercostal space just above sternum Cat—left side, second to third intercostal space one third of the way up from sternum Tricuspid valve (right apex) Dog—right side, third to fifth intercostal space near costochondral junction Cat—right side, fourth to fifth intercostal space near sternum
X-radiography of heart: Radiography of heart is useful in visualizing the shape and size of the heart. Enlargement of the heart can be assessed by VHS (vertebral heart sum/ vertebral heart score). The vertebral heart sum (VHS) is the sum of the long axis cardiac dimension (L) and the maximal perpendicular short axis dimension (S). S and L are measured in vertebral units beginning at T4. T4