Chapter 8: The Cardiovascular System Dr. Felix Hernandez M.D.

The Cardiovascular System: Examining the Heart and Blood Vessels Overview –Anatomy of the heart and great vessels –The heart as a pump, blood pressure –Beginning the examination — The vital signs: blood pressure and heart rate –Jugular venous pressure (JVP) and pulsations; carotid pulse –Chest wall and apical impulse/PMI –Auscultation: S1 and S2; S3 and S4 –Auscultation: describing cardiac murmurs

The Heart and Great Vessels: Anatomy

Know Your Surface Landmarks Can you count interspaces? –identify your own... the midsternal line the midclavicular line the anterior axillary line the midaxillary line

Visualize the Chambers of the Heart and Important Great Vessels Test yourself Can you visualize the circulation through: –the superior and inferior vena cavas –the right atrium and the right ventricle ventricle –the pulmonary arteries –the left atrium and left ventricle –the aorta and the aortic arch

The Heart as a Pump: Key Points for Examining the Heart Remember the heart chambers and valves and the forward flow of blood from right side of the heart through the pulmonary arteries and veins to the left side of the heart Combine this knowledge with careful examination and systematic clinical reasoning This will lead you to correct identification of valvular and congestive heart disease

The Heart as a Pump: The Cardiac Cycle of Systole and Diastole Systole — The ventricles contract –The right ventricle pumps blood into the pulmonary arteries (pulmonic valve is open) –The left ventricle pumps blood into the aorta (aortic valve is open) Diastole — The ventricles relax –Blood flows from the right atrium → right ventricle (tricuspid valve is open) –Blood flows from the left atrium → left ventricle (mitral valve is open)

The Heart As A Pump: Important Concepts Preload Volume Overload Contractility (ventricles contract during systole) Afterload Pressure Overload Cardiac output = stroke volume x heart rate Blood pressure = cardiac output x systemic vascular resistance

Blood Pressure Systolic Blood Pressure –Pressure generated by left ventricle (LV) during systole, when the LV ejects blood into the aorta and the arterial tree. Pressure waves in the arteries create pulses Diastolic Blood Pressure –Pressure generated by blood remaining in arterial tree during diastole, when the ventricles are relaxed

Beginning the Examination: The Vital Signs First Observe The Patient Then … Begin with the vital signs –Blood Pressure Select the proper size cuff Position the patient properly Make sure there is a brachial pulse Apply the cuff correctly! Assess blood pressure for hypertension –Heart Rate: radial vs. apical

Jugular Venous Pressure (JVP) and Pulsations Recall that the jugular veins reflect right atrial pressure Steps for examination –Raise the head of the bed or examining table to 30° –Turn the patient’s head gently to the left –Identify the topmost point of the flickering venous pulsations –Place a centimeter ruler upright on the sternal angle –Place a card or tongue blade horizontally from the top of the JVP to the ruler, making a right angle –Measure the distance above the sternal angle in centimeters – a centimeter elevation is normal

Assessing the Carotid Pulse Keep the patient’s head elevated to 30° Place your index and middle fingers on the right then the right carotid arteries, and palpate the carotid upstroke The upstroke may be: –Brisk, or normal –Delayed – suggests aortic stenosis, or –Bounding – suggests aortic insufficiency Listen with the stethoscope for any bruits

Palpating the Chest Wall Using the fingerpads, palpate for heaves or lifts from abnormal ventricular movements Using the ball of the hand, palpate for thrills, or turbulence transmitted to the chest wall surface by a damaged heart valve Palpate the chest wall in the aortic, pulmonic, left parasternal, and apical areas

Assessing the PMI, or point of maximal impulse Inspect the left anterior chest for a visible PMI Using you fingerpads, palpate at the apex for the PMI The PMI may be: –Tapping, or normal –Sustained — suggests LV hypertrophy from hypertension or aortic stenosis, or –Diffuse — suggests a dilated ventricle from congestive heart failure or cardiomyopathy Locate the PMI by interspace and distance in centimeters from the midsternal line

Listening to the Heart — Auscultation Listen in all 6 listening areas for S1 and S2 using the diaphragm of the stethoscope Then listen at the apex with the bell The diaphragm and the bell... –The diaphragm is best for detecting high-pitched sounds like S1, S2, and also S4 and most murmurs –The bell is best for detecting low-pitched sounds like S3 and rumble of mitral stenosis

Describing Heart Murmurs: Timing and Duration Identify and describe any murmurs Timing — are they systolic or diastolic? –Tip — palpate the carotid upstroke (occurs in systole) as you listen –If the murmur coincides with the carotid upstroke, it is systolic Duration early / mid / or late systolic early / mid / or late diastolic

Describing Heart Murmurs: Shape and Intensity Shape –Crescendo, decrescendo, or both (sometimes called diamond-shaped) Example, crescendo- decrescendo systolic murmur of aortic stenosis Crescendo Decrescendo Both

Describing Heart Murmurs: Shape and Intensity (cont.) Shape –Plateau... machinery Example, holosystolic murmur of mitral regurgitation Intensity — grade the murmur on a scale of 1 to 6 –grades /6 must have accompanying thrill Plateau Machinery

Describing Heart Murmurs: Quality,Pitch, and Location Quality –Apply terms like harsh, musical, soft, blowing, or rumbling Pitch –Apply terms like high, medium, or low-pitched Examples –Harsh 2/6 medium-pitched holosystolic murmur best heard at the apex—describes mitral regurgitation –Soft blowing 3/6 decrescendo diastolic murmur best heard at the lower left sternal border – describes aortic regurgitation