Presentation on theme: "Chapter 19 Disorders of Cardiac Function"— Presentation transcript:
1 Chapter 19 Disorders of Cardiac Function Essentials of PathophysiologyChapter 19 Disorders of Cardiac Function
2 PRE-LECTURE QUIZFTPericarditis represents an inflammatory process of the myocardium.All types of angina represent an acute myocardial infarction, also known as a heart attack.The heart extracts and uses 60% to 80% of the oxygen in blood flowing through the coronary arteries.Atherosclerosis is by far the most common cause of coronary heart disease.Stable atherosclerotic plaques tend to rupture more than unstable atherosclerotic plaques and lead to acute coronary syndromes, ranging from unstable angina to ST-segment elevation myocardial infarction.
3 PRE-LECTURE QUIZ Cardiac __________ is a life-threatening, slow or rapid compression of the heart due to the accumulation of fluid, pus, or blood in the pericardial sac.Rheumatic heart disease, a disorder that follows a group A _____________ throat infection, is of great concern because of the potential effects of chronic valvular disorders that produce permanent cardiac dysfunction and sometimes fatal heart failure years later.__________ refers to a narrowing of the valve orifice and failure of the valve leaflets to close properly. Creatine kinase, myoglobin, and troponin are known as serum cardiac __________ and are useful for acute myocardial infarction determination and classification.Coronary heart disease is a disorder of impaired __________ blood flow, usually caused by atherosclerosis.corornaryMarkersStenosisStreptococcalTamponade
4 Disorders That Affect the Whole Heart Pericardial disordersCoronary heart diseaseMyocardial diseasesThese disorders can cause symptoms of both right- and left-sided heart failure
6 Inflammation of the pericardium causes: PericarditisInflammation of the pericardium causes:PainExudateSerous pericardial effusionCardiac tamponade: rapid accumulation of exudate compresses the heartFibrous friction rub; adhesionsECG changes
7 Pericarditis (cont.)Inflammation of the pericardium may restrict the heart’s movement due to:Serous exudate filling the pericardial cavity (pericardial effusion)Fibrous scar tissue making the pericardium stick to the heart (constrictive pericarditis)
8 Consequences of Pericardial Effusion fluid in pericardialConsequences of Pericardial Effusioncavityrestricts heartexpansionleft ventricleright ventriclecannot acceptcannot acceptenough bloodenough blooddecreasedincreased venouscardiacpressure; jugularoutputdistensiondecreased bloodpressure andshock
9 QuestionWhat is the immediate treatment for severe cardiac tamponade?OxygenCardiac drugsSurgeryPericardiocentesis (removal of fluid from the sac with a needle)
10 Inflammation of the pericardium causes: PericarditisInflammation of the pericardium causes:PainExudateSerous pericardial effusionCardiac tamponade: rapid accumulation of exudate compresses the heartFibrous friction rub; adhesionsECG changes
11 Pericarditis (cont.)Inflammation of the pericardium may restrict the heart’s movement due to:Serous exudate filling the pericardial cavity (pericardial effusion)Fibrous scar tissue making the pericardium stick to the heart (constrictive pericarditis)
12 Consequences of Pericardial Effusion fluid in pericardialcavityConsequences of Pericardial Effusionrestricts heartexpansionleft ventricleright ventriclecannot acceptcannot acceptenough bloodenough blooddecreasedincreased venouscardiacpressure; jugularoutputdistensiondecreased bloodpressure andshock
13 (removal of fluid from the sac with a needle) QuestionWhat is the immediate treatment for severe cardiac tamponade?OxygenCardiac drugsSurgeryPericardiocentesis(removal of fluid from the sac with a needle)
14 AnswerPericardiocentesis (removal of fluid from the sac with a needle)Rationale: In severe cardiac tamponade, there is so much fluid in the pericardial sac compressing the heart that its function declines rapidly. The fluid must be removed quickly by inserting a needle into the pericardial space and aspirating the accumulated fluid.
15 Pulsus ParadoxusOn inhaling, the right ventricle fills with extra bloodWhen the right ventricle is overfilled, the left ventricle is compressed and cannot accept much blood. Because the heart cannot fully expandOn the next heartbeat, the left ventricle does not send out much blood: systolic BP drops
16 Coronary Heart Disease Atherosclerosis blocks coronary arteriesIschemia may cause:AnginaHeart attackCardiac arrhythmiasConduction deficitsHeart failureSudden death
21 Kinds of Angina Stable angina Pain when heart’s oxygen demand increasesVariant anginaPain when coronary arteries spasmSilent myocardial ischemiaMyocardial ischemia without pain
22 Acute Coronary Syndromes ECG changesT-wave inversionST-segment depression or elevationAbnormal Q waveSerum cardiac markersProteins released from necrotic heart cellsMyoglobin, creatine kinase, troponin
23 QuestionTell whether the following statement is true or false. Chronic ischemic heart disease is more likely to result in stable angina than acute coronary syndromes.
24 AnswerTrue Rationale: Ischemic heart disease is characterized by stable angina, which is associated with plaques that are fixed obstructions. Unstable angina is characterized by plaques with platelets stuck to them (these are likely to form a thrombus)—they cause a range of acute coronary syndromes.
25 Acute Myocardial Infarction Chest painSevere, crushing, constrictive, OR like heartburnSympathetic nervous system responseGI distress, nausea, vomitingTachycardia and vasoconstrictionAnxiety, restlessness, feeling of impending doomHypotension and shockWeakness in arms and legs
26 An Acute MI (AMI) Leaves Behind an Area of Yellow Necrosis
27 Complications of AMI Heart failure Cardiogenic shock Pericarditis ThromboemboliRupture of the heartVentricular aneurysms
28 Malfunctioning Heart Muscle Malfunctioning heart muscle can cause heart failure if:Ventricles are unusually thick so there is not a normal amount of room for blood inside them (hypertrophic cardiomyopathy)Ventricles are too stiff to stretch (restrictive cardiomyopathy)Ventricles are too weak to pump out the blood that is in them (MI, myocarditis, dilated cardiomyopathy)
30 Hypertrophic Cardiomyopathy Defects in their contractile proteins make cells too weakThey hypertrophy to do the same amount of work as normal cellsNeed more oxygen and perform less efficiently, so the person is prone to heart failure and may suffer sudden death during exertion
31 QuestionWhich type of cardiomyopathy is characterized by weakened ventricles?Dilated cardiomyopathyHypertrophic cardiomyopathyRestrictive cardiomyopathyPeripartum cardiomyopathy
32 AnswerDilated cardiomyopathyRationale: In dilated cardiomyopathy, the ventricles are too weak to pump blood, resulting in a diminished cardiac output (CO). The other types listed are caused by thick ventricles, stiff ventricles, or LV dysfunction in late pregnancy or postpartum, respectively.
33 Valvular Disorders and Heart Defects By interfering with normal blood flow, these often cause the signs and symptoms of left- or right-sided heart failurebodyrightleftheartheartlungs
34 The Endocardial Structures The endocardial structures lining the heart can cause heart failureIf the AV valves leading into the ventricles do not work (mitral or tricuspid problems)If the semilunar valves leading out of the ventricles do not work (aortic or pulmonary problems)
35 Arrange these steps in the proper order: Cardiac CycleDiscussion:Arrange these steps in the proper order:– Ventricles relax – First heart sound– Start Systole – Semilunar valves open– End Diastole – AV valves close– AV valves open – Semilunar valves close– Ventricles contract – Second heart sound64151039728
36 Valve Defects Each of the four valves can be defective Stenosis: valve will not open all the way; it is harder to force blood through itRegurgitation: valve will not close all the way; it leaks when it should be closedAlso called valvular insufficiency
37 QuestionTell whether the following statement is true or false. Mitral valve regurgitation results in a diminished stroke volume.
38 AnswerTrue Rationale: If the mitral valve does not close as it should, a portion of the stroke volume (amount of blood ejected by the ventricle/beat) leaks back into the left atrium, decreasing the amount of blood that is ejected during that beat (SV).
39 Discussion Defects in which valves might cause: Severe dependent edema?Paroxysmal nocturnal dyspnea?Congested liver?Distended jugular veins?Productive cough with frothy sputum?
40 Identifying Defective Valves The blood going through the valve makes a noiseThese are called heart murmursYou can identify them by:Where they are—which valve are they near?How they sound—high- or low-pitched?When they happen—systole or diastole?
41 When Will You Hear Murmurs? If a valve is stenotic, you will hear a murmur of blood shooting through the narrow opening when the valve is openIf a valve is regurgitant, you will hear a murmur of blood leaking back through when the valve should be closed
43 Valvular Disorders Mitral Regurgitation Aortic Valve Stenosis Part of SV goes back into the LAHeart has to work harder to meet body needsLV hypertrophyAortic Valve StenosisAortic valve is constrictedDifficult to pump blood from the LVLV hypertrophyMitral StenosisIncomplete LV fillingLower COAortic RegurgitationBlood flows backward into the LV from the AortaLV Dilatation
44 Congenital Heart Defects Atrial septal defectsVentricular septal defectsEndocardial cushion defectsPatent ductus arteriosusPulmonary stenosisTetralogy of FallotTransposition of the great vesselsCoarctation of the aorta
45 ShuntsA shunt is an opening or connection that lets blood move from one side of the circulation to the otherMost shunts occur in the heart and move blood either from the left to the right or from the right to the leftBecause the left side is stronger, blood is usually pushed from the left to the right side
46 Shunts (cont.) Shunts are normal before birth Foramen ovale Lets blood go from the right atrium to the left atrium to bypass the lungsDuctus arteriosusLets blood go from the pulmonary trunk to the aorta to bypass the lungsDuctus venosusLets blood go from the visceral veins to the vena cava, bypassing the liver
47 body left right heart heart lungs Less blood goes to body Left-to-right ShuntLess blood goes to bodybodyrightleftBlood moves from left to rightheartheartMore blood goes to lungslungs
48 body left right heart heart lungs Deoxygenated blood goes to body Right-to-left ShuntDeoxygenated blood goes to bodybodyrightBlood moves from right to leftleftheartheartLess blood goes to lungslungs
49 body left right heart heart lungs Discussion Show how the diagram would look for:Patent ductus arteriosusbodyrightleftheartheartlungs
50 body left right heart heart lungs Discussion Show how the diagram would look for:Transposition of the great vesselsbodyrightleftheartheartlungs
51 body left right heart heart lungs Discussion Show how the diagram would look for:Tetralogy of Fallotbodyrightleftheartheartlungs