Cardiac cycleduring systole:
-ventricles contract, ejecting blood from the left ventricle to the aorta; right ventricle to the pulmonary artery
-ventricular contraction raises the pressure in the ventricles and forces the mitral and tricuspid valves closed preventing back flow
-S1
-intraventricular pressure exceeds aorta and pulmonary artery so valves are opened and blood rushes through
-when ventricles are almost empty, pressure falls and SL valves close AKA S2
during diastole:
-ventricles dilate, and blood rushes in them as atria contract
-passive until ventricular filling is complete; filling sometimes produces S3
-then the atria contract to ensure the ejection of remaining blood which sometimes produces S4Split S2aortic valve closes slightly before the pulmonic, heard as two componentsElectrical activity: impulses-intrinsic conduction system enables the heart to contract
-an electrical impulse stimulates each myocardial contraction
-originates in and is paced by the sinoatrial node to the atrioventricular node to the bundle of His to the Purkinje fibersECGgraphic recording of electrical activity during the cardiac cycle
-records electrical current generated by the movement of ions in and out of the myocardial cell membranes
-records
1. depolarization (spread of a stimulus through the heart muscle)
2. repolarization (return of the stimulated heart muscle back to a resting state)`ECG wavesP wave: spread of a stimulus through the atria
PR interval: time from initial stimulation of the atria to initial stimulation of the ventricles
QRS complex: spread of a stimulus through the ventricles
ST segment and T wave: return of stimulated ventricular muscle to a resting state
U wave: small deflection rarely seen, thought to be related to repolarization of the Purkinje fibers
QT interval: time elapsed from the onset of ventricular depolarization until the completion of ventricular repolarizationInfants and children-fetal circulation compensates for the nonfunctional fetal lungs
-blood flows from the right ventricle into the left via the foramen ovale
-the right ventricle pumps blood through the patent ductus arteriosus rather than into the lungs
-the changes at birth include closure of the ductus arteriosus usually within 24-48 hours & the functional closure of the interatrial foramen ovale as pressure raises in the left atrium
-lies more horizontallyPregnant women-maternal blood volume over the pre pregnancy level due to an increase in plasma volume
-heart works harder to accommodate the increased heart rate and stroke volume required for the expanded blood volume
-returns to normal within 3-4 weeks after deliveryOlder adults-heart size may decrease with age unless hypertension or heart disease causes enlargement
-left ventricular wall thickens
-valves tend to fibrous and calcify
-SV decreases
-endocardium thickens
-myocardium becomes less elastic
-cardiac function is further compromised by fibrosis and sclerosisHistory of present illnesschest pain:
-onset and duration-what was pt doing when it occurred
-character
-location
-severity
-associated symptoms
-self treatment
-medicationsPast medical history-cardiac surgery or hospitalization for cardiac reasons
-congenital heart disease
-rhythm disorder
-acute rheumatic fever
-kawasaki disease
-chronic illnessFamily history-long QT syndrome
-Marfan syndrome
-diabetes
-heart disease
-dyslipidemia
-hypertension
-obesity
-congenital heart diseasePersonal and social history-employment
-tobacco use
-nutritional status
-usual diet
-weight
-alcohol consumption
-known hypercholesterolemia
-relaxation/hobbies
-exercise
-illicit drugsInfants-tiring easily/sweating with feeding
-breathing changes
-cyanosis
-excessive weight gain compared to caloric intake
-mother's health during pregnancyChildren-tiring during play
-naps
-headaches
-nosebleeds
-unexplained joint pain
-expected height and weight gain
-expected physical and cognitive developmentPregnant women-history of cardiac disease or surgery
-dizziness or syncopeOlder adults-common symptoms: confusion, dizziness, blackouts, syncope, palpitations, coughs and wheezes, shortness of breath, chest pain, fatigue, leg edema
-if diagnosed: drug reactions, digitalis toxicity, interference with ADLs, orthostatic hypotensionExamination-inspection
-palpation
-percussion
-auscultationInspection-most adults apical impulse is about the midclavicular line in the fifth left intercostal space
-should only be seen in one intercostal space if healthy
-may become visible only when the pt sits up and the heart is brought closer to anterior wallPalpation-with pt supine, palpate precordium
-touch lightly and let the cardiac movements rise to your hand
-begin at apex then move to the inferior left sternal border then up the sternum to the base and down the right sternal border and into the epigastric or axillae
-feel for apical pulse: point at which apical impulse is most readily seen or felt is the point of maximal impulse
-if apical impulse is more vigorous than expected classify as a heave or lift
-feel for a thrill (a fine, palpable rushing vibration, a palpable murmur- generally indicates turbulence or a disruption of the expected blood flow
-while palpating the precordium, use other hand to palpate the carotid arteryPercussion-tap at anterior axillary line, moving medially along the intercostal spaces toward sternal border
-the change from a resonant to a dull note marks the cardiac borderAuscultation-make sure pt is warm, relaxed; and the room quiet
-sound is transmitted in the direction of blood flow
-use firm pressure for the diaphragm
-use light pressure for the bell
-five traditional ausculatory areas
1. aortic valve area- second right intercostal space at the right sternal border
2. pulmonic valve area- second left intercostal space at the left sternal border
3. second pulmonic area-third left intercostal space at the left sternal border
4. tricuspid area- fourth left intercostal space along the lower left sternal border
5. mitral area-at the apex in the fifth left intercostal space at the midclavicular line
-inhaling deeply with separate S2 into two componentsBasic heart sounds-characterized by pitch, intensity, duration, and timing in the cardiac cycleHeart murmurs-relatively prolonged extra sounds heard during systole or diastole
-often indicate a problem
-caused by some disruption in the blood flow
-diseased valves do not open/close well
-not all caused by valvular defectsTypes of heart murmurs-mitral stenosis
-aortic stenosis
-subaortic stenosis
-pulmonic stenosis
-tricuspid stenosis
-mitral regurgitation
-mitral valve prolapse
-aortic regurgitation
-pulmonic regurgitation
-tricuspid regurgitationRhythm disturbance-determine regularity of heart rhythm, should be regular
-if irregular, determine if there is a pattern
-regular irregular: sinus arrhythmia
-irregular irregular: heart disease or conduction system impairmentInfants-examine within first 24 hours of birth and again 2-3 days later
-note skin color, cyanosis, enlargement of heart
-expect to see and palpate the apical impulse at the fourth to fifth left intercostal space just medial to the midclavicular lineChildren-sinus arrhythmia are commonOlder adults-may need to slow pace of examination
-ectopic beats are fairly commonAnginapain caused by myocardial ischemiaBacterial endocarditisbacterial infection of the endothelial layer of the heart and valvesCongestive Heart Failure (Left sided)heart fails to propel blood forward with usual force, result in congestion in the pulmonary circulationCongestive Heart Failure (Right sided)heart fails to propel blood forward with its usual force, resulting in congestion in the systemic circulationPericarditisinflammation of the pericardiumCardiac Tamponadeexcessive accumulation of effused fluids or blood between the pericardium and the heartCor pulmonaleenlargement of the right ventricle secondary to chronic lung diseaseMyocardial Infarctionischemic myocardial necrosis caused by abrupt decrease in coronary blood flow to a segment of the myocardiumMyocarditisfocal or diffuse inflammation of the myocardiumConduction disturbanceseither proximal to the bundle of His or diffusely throughout the conduction systemSick sinus syndromearrhythmias caused by a malfunction of the sinus nodeTetralogy of Fallotcongenital heart defect composed of four cardiac defects: ventricular septal defect, pulmonic stenosis, dextroposition of the aorta, and right ventricular hypertrophyVentricular septal defectopening between the left and right ventriclesPatent ductus arteriosusfailure of the ductus arteriosus to close after birthAtrial septal defectcongenital defect in the septum dividing the left and right atriaAcute rheumatic feversystemic connective tissue disease occurring after streptococcal pharyngitis or skin infectionAtherosclerotic heart disease- CHDnarrowing of the small blood vessels that supply blood and oxygen to the heartmitral insufficiency, regurgitationabnormal leaking of blood through the mitral valve, from left ventricle to left atriumSenile cardiac amyloidosisamyloid, fibrillary protein produced by chronic inflammation or neoplastic disease, deposition in the heart
