Congenital Heart Disease- Ettinger Flashcards
(30 cards)
Innocent murmurs are usually of low intensity (grade I-II/VI), ……….- or ………..systolic in timing, and best heard at the left heart base. They often vary in intensity coincident with changes in heart rate or body position. Innocent murmurs usually, but not invariably, diminish or resolve as the animal reaches 6 months of age; however, soft systolic innocent murmurs can persist well into adulthood, especially in large-breed dogs.
Innocent murmurs are usually of low intensity (grade I-II/VI), proto- or midsystolic in timing, and best heard at the left heart base. They often vary in intensity coincident with changes in heart rate or body position. Innocent murmurs usually, but not invariably, diminish or resolve as the animal reaches 6 months of age; however, soft systolic innocent murmurs can persist well into adulthood, especially in large-breed dogs.
Cardiac murmurs caused by congenital disease are typically louder (grade III-VI/VI) and of longer duration than innocent murmurs, often obscuring the normal heart sounds. Murmurs of this description are unlikely to be innocent and additional diagnostics are warranted;
Cardiac murmurs caused by congenital disease are typically louder (grade III-VI/VI) and of longer duration than innocent murmurs, often obscuring the normal heart sounds. Murmurs of this description are unlikely to be innocent and additional diagnostics are warranted;
In animals with large septal defects, including severe atrioventricular …………………… and some forms of serious ……………. heart disease, the heart murmur may be soft or even inaudible.
In animals with large septal defects, including severe atrioventricular valve dysplasia and some forms of serious cyanotic heart disease, the heart murmur may be soft or even inaudible.
Abnormalities of the arterial pulse, mucous membranes, jugular veins, or precordial impulse may support a suspicion of congenital heart disease.
Hyperkinetic and bounding (“waterhammer”) arterial pulses are characteristic of lesions causing abnormal ……………… run-off of aortic blood and low arterial …………….pressure, such as …………………. or severe ………………..
Hypokinetic pulses are typical of moderate to severe…………………………. (i.e., ………………) or other severe defects accompanied by low left ventricular output.
Hyperkinetic and bounding (“waterhammer”) arterial pulses are characteristic of lesions causing abnormal diastolic run-off of aortic blood and low arterial diastolic pressure, such as patent ductus arteriosus or severe aortic regurgitation. Hypokinetic pulses are typical of moderate to severe left ventricular outflow obstruction (i.e., subaortic stenosis) or other severe defects accompanied by low left ventricular output.
Visible cyanosis develops when the partial pressure of arterial oxygen falls below ……….. mm Hg and reduced (unoxygenated) arterial hemoglobin reaches ….. g/100 mL.
Cyanosis in animals with congenital heart disease is usually caused by a …………… to …………. (right-to-left) shunt at the level of the heart or great vessels.
Distended jugular veins indicate elevated ……………..pressure, which is usually caused by an abnormality of the right side of the heart, such as……………. dysplasia or ………………
Visible cyanosis develops when the partial pressure of arterial oxygen falls below 45 mm Hg and reduced (unoxygenated) arterial hemoglobin reaches 5 g/100 mL.
Cyanosis in animals with congenital heart disease is usually caused by a systemic to pulmonary (right-to-left) shunt at the level of the heart or great vessels.
Distended jugular veins indicate elevated central venous pressure, which is usually caused by an abnormality of the right side of the heart, such as tricuspid valve dysplasia or pulmonic stenosis.
A precordial impulse of increased strength or area often indicates enlargement of the underlying ventricle(s). The presence of a precordial thrill defines the most intense cardiac murmurs (grade V-VI/VI). The focus of this vibration is synonymous with the point of maximal acoustic intensity, and is characteristic of the associated underlying defect.
A precordial impulse of increased strength or area often indicates enlargement of the underlying ventricle(s). The presence of a precordial thrill defines the most intense cardiac murmurs (grade V-VI/VI). The focus of this vibration is synonymous with the point of maximal acoustic intensity, and is characteristic of the associated underlying defect.
Distinctive laboratory abnormalities may occur in animals with cyanotic heart disease (i.e., tetralogy of Fallot, reversed patent ductus arteriosus), and include arterial …………….., …………………., metabolic ……………., and ……………… (4). However, in most cases, hematologic testing is not an important part of congenital heart disease evaluation. Although serum biochemical tests may be abnormal in the presence of congestive heart failure or concurrent organ disease, the biochemical profile and urinalysis are typically normal.
Distinctive laboratory abnormalities may occur in animals with cyanotic heart disease (i.e., tetralogy of Fallot, reversed patent ductus arteriosus), and include arterial hypoxemia, hypocarbia, metabolic acidosis, and erythrocytosis. However, in most cases, hematologic testing is not an important part of congenital heart disease evaluation. Although serum biochemical tests may be abnormal in the presence of congestive heart failure or concurrent organ disease, the biochemical profile and urinalysis are typically normal.
An ECG indicating a ……………… shift in the mean electrical axis and right ventricular hypertrophy immediately suggests the possibilities of ……………., ………………., or ………………………… Such an ECG would be rare in dogs with predominantly left-sided disease, such as mitral dysplasia or subaortic stenosis.
An ECG indicating a rightward shift in the mean electrical axis and right ventricular hypertrophy immediately suggests the possibilities of pulmonic stenosis, tetralogy of Fallot, or tricuspid valve dysplasia. Such an ECG would be rare in dogs with predominantly left-sided disease, such as mitral dysplasia or subaortic stenosis.
Conduction delay with right mean electrical axis deviation and widening of the QRS complex (partial or complete right bundle branch block) can indicate?
Pronounced right ventricular enlargement, congenital right bundle branch block, or the combined presence of both abnormalities.
Supraventricular arrhythmias, such as atrial tachycardia and atrial fibrillation are prone to occur in animals with congenital defects causing marked atrial enlargement, such as mitral or tricuspid valve dysplasia. Ventricular arrhythmias are common in disorders resulting in arterial hypoxemia, extreme hypertrophy of the ventricular myocardium, or reduced myocardial perfusion. Relevant examples include pups with tetralogy of Fallot or subvalvular aortic stenosis. Rhythm disorders with a genetic basis are being recognized with increasing frequency in juvenile and adult cats and dogs.
Supraventricular arrhythmias, such as atrial tachycardia and atrial fibrillation are prone to occur in animals with congenital defects causing marked atrial enlargement, such as mitral or tricuspid valve dysplasia. Ventricular arrhythmias are common in disorders resulting in arterial hypoxemia, extreme hypertrophy of the ventricular myocardium, or reduced myocardial perfusion. Relevant examples include pups with tetralogy of Fallot or subvalvular aortic stenosis. Rhythm disorders with a genetic basis are being recognized with increasing frequency in juvenile and adult cats and dogs.
X-ray: Aneurysmal dilation of the proximal ascending aorta is typical for ………………..and …………………., while dilation of the proximal descending aorta is typical of ………………… Dilation of the main pulmonary artery can develop as a consequence of ………………or ………………….., ………………., or …………………….
Aneurysmal dilation of the proximal ascending aorta is typical for subvalvular aortic stenosis and aortic insufficiency, while dilation of the proximal descending aorta is typical of patent ductus arteriosus. Dilation of the main pulmonary artery can develop as a consequence of pulmonic stenosis or insufficiency, increased pulmonary blood flow caused by a left-to-right shunt, or pulmonary hypertension.
X-ray: Left-to-right shunts potentiate pulmonary blood flow, increasing the …………….., ……………. and prominence of the pulmonary …………. and ……………., whereas right-to-left shunts reduce ……………………, resulting in diminished ………… and reduced ……………. of the pulmonary ………….. and ………….
Animals with decompensated or impending congestive heart failure may show selective widening of the caudal vena cava (………. heart failure) or pulmonary veins (………….).
Left-to-right shunts potentiate pulmonary blood flow, increasing the number, diameter and prominence of the pulmonary arteries and veins, whereas right-to-left shunts reduce pulmonary flow, resulting in diminished prominence and reduced diameters of the pulmonary arteries and veins. Animals with decompensated or impending congestive heart failure may show selective widening of the caudal vena cava (right heart failure) or pulmonary veins (left heart failure).
The Bernoulli equation is a powerful tool that allows the examiner to estimate the hydrostatic (blood) pressure difference between individual cardiac chambers.
The Bernoulli equation is a powerful tool that allows the examiner to estimate the hydrostatic (blood) pressure difference between individual cardiac chambers.
To assure accurate measurements, the cursor must be positioned within 20 degrees of parallel along the main direction of blood flow
CARDIAC CATHETERIZATION AND ANGIOGRAPHY.
Cardiac catheterization is mainly reserved to attempt repair of certain congenital defects (e.g., balloon valvuloplasty for pulmonic stenosis and device occlusion of patent ductus arteriosus) or to clarify ambiguous anatomic lesions when surgery is contemplated.
In selected cases, diagnostic cardiac catheterization is warranted to verify pressure estimates derived from Doppler echocardiographic studies, to collect blood for oximetry, to measure cardiac output, or to examine structures not accessible to echocardiographic interrogation, such as the peripheral pulmonary or systemic vasculature.
In selected cases, diagnostic cardiac catheterization is warranted to verify pressure estimates derived from Doppler echocardiographic studies, to collect blood for oximetry, to measure cardiac output, or to examine structures not accessible to echocardiographic interrogation, such as the peripheral pulmonary or systemic vasculature.
Selective catheterization of the heart involves the introduction of specially designed catheters into a peripheral vessel and their guidance into specific cardiac chambers or great vessels to enable the measurement of intracardiac and vascular pressures, ………………, and ……….. content (………………….). Such studies are performed before angiographic imaging as all radiopaque contrast agents can alter vascular tone and cardiac performance. Vascular and intracardiac pressures are measured either by attaching the proximal end of fluid-filled catheters to a pressure-sensing transducer or by the use of specially designed catheters with microtransducers incorporated into their distal end. Pressures are then displayed and saved via a digital or analog physiologic recorder.
Selective catheterization of the heart involves the introduction of specially designed catheters into a peripheral vessel and their guidance into specific cardiac chambers or great vessels to enable the measurement of intracardiac and vascular pressures, cardiac output, and oxygen content (oximetry). Such studies are performed before angiographic imaging as all radiopaque contrast agents can alter vascular tone and cardiac performance. Vascular and intracardiac pressures are measured either by attaching the proximal end of fluid-filled catheters to a pressure-sensing transducer or by the use of specially designed catheters with microtransducers incorporated into their distal end. Pressures are then displayed and saved via a digital or analog physiologic recorder.
Peak systolic pressure in the left ventricle and aorta is approximately …… times that in the right ventricle and pulmonary artery. Since the systemic and pulmonary circulations are connected in series and the cardiac output from the left and right ventricles is balanced, it can be appreciated that pulmonary vascular ……………… is much lower than systemic vascular resistance. Blood flowing through the heart moves from areas of high to low resistance, and therefore from areas of high to low ……………
For instance, left ventricular systole produces a small instantaneous pressure gradient between the left ventricle and aorta, causing opening of the aortic valve and commencement of left ventricular outflow. It is important to note, however, that once the aortic valve is open, the pressures in the ventricle and aorta quickly ………..
In contrast, a pressure gradient during systole is maintained between the left ventricle and left atrium because of the presence of the intervening and closed mitral valve. Should the aortic valve not open completely, pressure between the left ventricle and aorta …………. equalize, and a pressure gradient (increased pressure proximal to the obstruction, relative to the pressure distal to the obstruction) is maintained during the entirety of systole. This pressure gradient is needed to maintain normal flow through the stenotic aortic valve.
Peak systolic pressure in the left ventricle and aorta is approximately 4 times that in the right ventricle and pulmonary artery. Since the systemic and pulmonary circulations are connected in series and the cardiac output from the left and right ventricles is balanced, it can be appreciated that pulmonary vascular resistance is much lower than systemic vascular resistance. Blood flowing through the heart moves from areas of high to low resistance, and therefore from areas of high to low pressure.
For instance, left ventricular systole produces a small instantaneous pressure gradient between the left ventricle and aorta, causing opening of the aortic valve and commencement of left ventricular outflow. It is important to note, however, that once the aortic valve is open, the pressures in the ventricle and aorta quickly equalize.
In contrast, a pressure gradient during systole is maintained between the left ventricle and left atrium because of the presence of the intervening and closed mitral valve. Should the aortic valve not open completely, pressure between the left ventricle and aorta does not equalize, and a pressure gradient (increased pressure proximal to the obstruction, relative to the pressure distal to the obstruction) is maintained during the entirety of systole. This pressure gradient is needed to maintain normal flow through the stenotic aortic valve.
Thus an intracardiac pressure gradient is indicative of an obstructive lesion, and its severity correlates to the magnitude of the obstruction. A systolic pressure gradient between the right ventricle and main pulmonary artery, consistent with pulmonic stenosis, is shown in Figure 249-1.
Thus an intracardiac pressure gradient is indicative of an obstructive lesion, and its severity correlates to the magnitude of the obstruction. A systolic pressure gradient between the right ventricle and main pulmonary artery, consistent with pulmonic stenosis, is shown in Figure 249-1.
Pressure, resistance, and ………… (cardiac output) are interrelated so that the magnitude of a pressure gradient across obstruction varies with flow; it can be diminished by heart failure, anesthesia, or hypovolemia, and can be increased by exercise, anemia, or excitement.
Pressure, resistance, and flow (cardiac output) are interrelated so that the magnitude of a pressure gradient across obstruction varies with flow; it can be diminished by heart failure, anesthesia, or hypovolemia, and can be increased by exercise, anemia, or excitement.
The configuration of the pressure waveforms are also altered in predictable ways by congenital heart defects. In dogs with severe subvalvular aortic stenosis, the slope of the aortic pressure …… and the peak systolic pressure are ………………..
In cases of patent ductus arteriosus, ………… run-off of aortic blood into the pulmonary artery reduces the systemic …………….. pressure, and the ……………………….. (the difference between the peak systolic and diastolic pressure) increases.
The configuration of the pressure waveforms are also altered in predictable ways by congenital heart defects. In dogs with severe subvalvular aortic stenosis, the slope of the aortic pressure rise and the peak systolic pressure are decreased.
In cases of patent ductus arteriosus, diastolic run-off of aortic blood into the pulmonary artery reduces the systemic diastolic pressure, and the pulse pressure (the difference between the peak systolic and diastolic pressure) increases.
Figure 249-1 Intracardiac pressure tracing from a 1-year-old mixed-breed dog obtained during catheterization of the right heart and pulmonary artery. The pulmonary artery pressures are normal. There is a systolic pressure gradient between the right ventricle and pulmonary artery of 75 mm Hg, indicating the presence of an obstruction to right ventricular outflow (in this case, valvular pulmonic stenosis). There is also a small diastolic pressure gradient between the pulmonary artery and right ventricle, which is caused by the diastolic closure of the pulmonic valve, and is a normal finding. The electrocardiogram displays a deep S wave, which is often found in animals with pulmonic stenosis and secondary right
Figure 249-1 Intracardiac pressure tracing from a 1-year-old mixed-breed dog obtained during catheterization of the right heart and pulmonary artery. The pulmonary artery pressures are normal. There is a systolic pressure gradient between the right ventricle and pulmonary artery of 75 mm Hg, indicating the presence of an obstruction to right ventricular outflow (in this case, valvular pulmonic stenosis). There is also a small diastolic pressure gradient between the pulmonary artery and right ventricle, which is caused by the diastolic closure of the pulmonic valve, and is a normal finding. The electrocardiogram displays a deep S wave, which is often found in animals with pulmonic stenosis and secondary right
Elevation of end-diastolic pressure is a subtle but important abnormality that can be identified by a ventricular pressure recording.
- Volume overloading from regurgitant valvular lesions
- Volume overloading from left-to-right shunts,
- By increased diastolic ventricular stiffness associated with ventricular concentric hypertrophy or myocardial fibrosis, or by pericardial disease.
Substantial increases of ventricular end-diastolic pressures (>……to ……. mm Hg) herald the development of overt congestive heart failure (i.e., edema, effusion, ascites).
Pressures in the right (measured directly) and left atrium (estimated by measuring ………………….) increase as an unavoidable consequence of high ventricular ……….-…………………. pressure.
Substantial increases of ventricular end-diastolic pressures (>15 to 20 mm Hg) herald the development of overt congestive heart failure (i.e., edema, effusion, ascites).
Pressures in the right (measured directly) and left atrium (estimated by measuring pulmonary wedge pressure) increase as an unavoidable consequence of high ventricular end-diastolic pressure.
Stenosis of the AV valves is characterized by elevated atrial and normal ventricular ……………… pressure, producing a measurable …………. pressure gradient across the affected valve.
Stenosis of the AV valves is characterized by elevated atrial and normal ventricular diastolic pressure, producing a measurable diastolic pressure gradient across the affected valve.
Transmission of ventricular systolic pressure to the atria across an incompetent AV valve results in ventricularization of the atrial pressure tracing and elevated mean …… ……………
Transmission of ventricular systolic pressure to the atria across an incompetent AV valve results in ventricularization of the atrial pressure tracing and elevated mean atrial pressure.
