Cardiology Flashcards
What are some indications for an EKG?
- Chest pain
- Syncope
- Cyanotic episodes
- Drug ingestion
- CHD evaluation
- Palpitations
- Pericarditis
- Kawasaki disease
- myocarditis
- Rheumatic heart fever
- Family history of sudden death
- electrolyte abnormalities
What is the criteria for RVH on EKG?
- Pure R wave in V1 > 10mm
- Upright T wave in V1
- RSR’ pattern in V1, where R’ > 15mm ( 10mm (>1yo)
What can prolong PR interval?
- Increased vagal tone
- Heart block
- Endocarditis with abscess
- Hyperkalemia
- Digoxin toxicity
- Wolf-Parkinson-White
- Glycogen storage disease
What can prolong QRS? (>0.08msec if 0.10msec if >8yo)
- Bundle branch block
- Junctional or ventricular rhythm (not through His-Purkinje)
How do you correct QT for heart rate?
Bazett formula:
From start of Q to end of T
QTc=QT/(RR)^1/2
What is a normal QTc?
upper limit of normal: 450msec
Normal axis on EKG?
0 to 90: +I, +II and +aVF
Left axis deviation on EKG?
0 to -90: +I, +aVL and -aVF
Right axis deviation on EKG?
90 to 180: -I, +III and +aVF
Extreme right axis deviation on EKG?
-90 to -180: -I, -aVF and +aVR
What is Congestive Heart Failure?
Clinical syndrome defined as the inadequate oxygen delivery by the myocardium to meet the metabolic demands of the body
What’s the pathophysiology of CHF?
*Hypoperfusion of end organs:
-It stimulates the heart to maximize contractility and
heart rate in an attempt to increase cardiac output
- It also signals the kidneys to retain salt and water through the reninangiotensin system in an attempt to increase blood volume
- Catecholamines
- Released by the sympathetic nervous system also increase heart rate and myocardial contractility
What congenital lesions may cause increased pulmonary blood flow leading to CHF?
- A large ventricular septal defect (VSD)
- A large patent ductus arteriosus (PDA)
- Transposition of the great arteries (TGA)
- Truncus arteriosus
- Total anomalous pulmonary venous connection (TAPVC)
What obstructive congenital lesions can lead to CHF?
- Severe aortic, pulmonary, and mitral valve stenosis
- Coarctation of the aorta
- Interrupted aortic arch
- Hypoplastic left heart syndrome
What are other congenital causes of CHF?
- Arteriovenous malformations
- Mitral or tricuspid regurgitation, which overload portions of the heart
What are some acquired heart diseases that can cause CHF?
- Viral myocarditis (common cause of CHF in older children and adolescents)
- Other cardiac infections (endocarditis, pericarditis)
- Metabolic diseases (hyperthyroidism)
- Medications (doxorubicin, a chemotherapeutic agent)
- Cardiomyopathies
- Ischemic diseases
- Dysrhythmias (including tachycardia and bradycardia)
What are some miscellaneous causes of CHF?
-Severe anemia (which may cause high-output CHF)
-Rapid infusion of intravenous fluids (especially in premature infants)
-Obstructive processes of the airway (such as enlarged tonsils or adenoids, laryngomalacia, and cystic fibrosis), which may cause CHF as a result of chronic
hypoxemia that results in right-sided heart failure
What’s evidence of pulmonary congestion in CHF?
- Tachypnea
- Cough
- Wheezing
- Rales
- Pulmonary edema on chest radiograph
What’s evidence of impaired myocardial performance in CHF?
- Tachycardia
- Sweating
- Pale or ashen skin color
- Diminished urine output
- Enlarged cardiac silhouette on CXR
What’s evidence of systemic venous congestion in CHF?
-Hepatomegaly and peripheral edema
What are other signs and symptoms of CHF?
- Failure to thrive
- Poor feeding (common symptom in newborns)
- Exercise intolerance (common symptom in older children and adolescents)
What are late manifestations of CHF?
-Cyanosis and shock
What are the goals of management of CHF?
To improve myocardial function and relieve
pulmonary and systemic congestion
What is the role of cardiac glycosides (digoxin) in the treatment of CHF?
Increase the efficiency of myocardial contractions and relieve tachycardia
What is the role of loop diuretics (furosemide, ethacrynic acid) in the treatment of CHF?
Reduce intravascular volume by maximizing sodium loss, which in turn leads to diminished ventricular dilation and
improved function
What is the role of loop inotropic medications (dobutamine, dopamine) in the treatment of CHF?
They are administered intravenously and may be used to treat severe CHF
