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Atrial and Ventricular Enlargement. Chapter 6. Cardiac Enlargement . dilation stretched congestive heart failure hypertrophy increase size of heart muscle fibers aortic stenosis. Cardiac Enlargement . Increase amount of cardiac tissue How would this affect amount of depolarization?
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Atrial and Ventricular Enlargement • Chapter 6
Cardiac Enlargement • dilation • stretched • congestive heart failure • hypertrophy • increase size of heart muscle fibers • aortic stenosis
Cardiac Enlargement • Increase amount of cardiac tissue • How would this affect amount of depolarization? • How could that affect an ECG?
Right Atrial Abnormality • Overload of the right atria • dilation • hypertrophy • Increase voltage of the P wave
Right Atrial Abnormality • Normal P wave amplitude is less than 2.5 mm and 0.12 seconds in width. • Abnormal P waves are typically taller than 2.5 mm but not longer the 0.12 sec.
Right Atrial Abnormality • Causes: • Pulmonary disease • Congenital heart disease
Right Atrial Abnormality • Tall P waves in any of the following leads: • II, III, aVF or sometimes V1.
Right Atrial Abnormality • P pulmonale • artial enlargement due to severe pulmonary disease • Atrial enlargement can occur in the absence of tall P waves.
Left Atrial Abnormality • Left atria normally depolarizes after the right atria. • Left atrial enlargement should prolong the P wave greater than 0.12 sec. • P wave height may be normal or increased
Left Atrial Abnormality • CAD may produce wide P waves without left atrial enlargement.
Left Atrial Abnormality • Leads I and/or II may show notched P waves • (second hump due to delayed depolarization of the left atrium) • (P mitrale: mitral valve disease) • V1 may show a bi-phasic P wave • negative part is > 0.4 sec. or 1 mm in depth • (right atria is anterior to the left atria)
Left Atrial Abnormality • Causes: • Valvular heart disease • Hypertensive heart disease • Cardiomyopathies • CAD
Right Ventricular Hypertrophy • What do you think will happen to the ECG with ventricular hypertrophy?
Normal QRS V6? V6? V1? V1? FIG. 4-6
Normal QRS V1 V6
Right Ventricular Hypertrophy • Consider right ventricular hypertrophy and V1 NORMAL HYPERTROPHY
Right Ventricular Hypertrophy • In V1, R wave is greater than the S wave • In V1, T wave inversion (reason unknown) • Right axis deviation
Right Ventricular Hypertrophy • Causes of RVH • congenital heart disease • atrial septal defects • others • Emphysema may mask signs of RVH
Left Ventricular Hypertrophy • With LVH, the electrical balance is tipped even further to the left. • Predominate S waves in the right chest leads • Tall R waves in the left chest leads
Left Ventricular Hypertrophy • If S wave in V1 + R wave in either V5 or V6> 35 mm (not specific indicator). • R wave > 11-13 mm in aVL • ST segment changes • Left axis deviation • Left atrial abnormality
Left Ventricular Hypertrophy • Causes: • Hypertension • Aortic stenosis • Risks of LVH • congestive heart failure • arrhythmias
Left Ventricular Hypertrophy • High voltage can be seen in normal people, especially athletes • Hypertrophy in both ventricles the ECG will show more evidence of LVH