aging of cardiac muscle and cardiac failure dr. franco navazio
Post on 19-Dec-2015
216 views
TRANSCRIPT
![Page 1: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/1.jpg)
Aging of Cardiac Muscle and
Cardiac Failure
Dr. Franco Navazio
![Page 2: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/2.jpg)
Aging Heart in the Elderly
In absence of specific disease the heart adjusts very well to advancing age.
![Page 3: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/3.jpg)
Myocardium: Cardiac muscle syncytium (multi-nucleated)
Endocardium: Internal layer of heart
Pericardium: External connective tissue layer of heart
Valves: openings between cardiac chambers (atrial ventricular) or between heart the arteries (aorta and pulmonary)
Conduction system: sinoatrial node (SA) is the pacemaker; also atrial ventricular node (AV), Bundle of His, Purkinje system
![Page 4: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/4.jpg)
Aging Heart: Physiology
Decline in the VO2 Max with advancing age
Minor decline in the cardiac outputImportant Variables: –physical conditions–dietary habits
Conclusions: Physically fit elderly people have a cardiac physiology similar to younger
individuals
![Page 5: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/5.jpg)
Physiological Changes with Age
Parameter 20 years 60 years
VO2 Max (mL x kg x min)
39 29
Maximum Heart Rate 194 162
Resting Heart Rate 63 62
Max. Cardiac Output (L x min)
22 16
EJECTION FRACTION 70-80% 50-55%
Resting BP 120/80 130/80
Total Lung Capacity (L)
6.7 6.5
Vital Capacity (L) 5.1 4.4
Residual Lung Volume (L)
1.5 2.0
Body Fat % 20.1 22.3
![Page 6: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/6.jpg)
Cardiovascular Changes with AgeHypertension: most common treatable cardiovascular change in the
elderlyDefinition: values above 140/90
In young, if standing BPincreases slightly but in elderly it may drop up to 20 mmHg
Systolic mumur: 50% of elderly but of very short durationEKG (or ECG): only nonspecific changes due to aging in voltage and nonspecific RBBBHypotension: diminished baro-reflex response in the elderly. With age, cerebral blood flow but autoregulation acts in a compensatory fashion; some patients maybe affected by symptomatic orthostatic hypotensionOrthostatic hypotension: drop of 20 mmHg in the systolic and 10 or more in the diastolic BP on standing upright
*MEMO as well as the post-prandial hypotension
![Page 7: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/7.jpg)
Pathology of the Aging Heart
Changes due to: • Normal Aging Processes• Superimposed Processes
(i.e. endocarditis)•Residuals of other conditions (i.e. hypertension, bicuspid,
aortic valve
![Page 8: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/8.jpg)
Aging Heart• Size: can atrophy, remain unchanged or develop moderate hypertrophy. The normal aging heart demonstrates a modest in L ventricular wall thickness. Possible enlargement of the L atrium and L ventricular cavity.
• Cardiac myocytes: in size, not numbers (some replaced with fibrous tissue). Cardiac myocytes effective in reentering the cell cycle & proliferating, partly offsetting cell loss due to necrosis or apoptosis.
• Amyloid deposition: half of those +70 years have some amyloid deposits in the heart but mostly in small amount & confined to the atria. Amyloid is not present in all elderly persons, not even in centenarians.
![Page 9: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/9.jpg)
Aging Heart
• Vasculature (atherosclerosis)– Walls of large arteries thicken, vessels become dilated and elongated
– Increase intimal thickness (due to cellular and matrix deposition)
– Fragmentation of the internal elastic membrane
• Cardiac output (L x min)– not decreased in healthy older men– slightly decreased in older women
![Page 10: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/10.jpg)
Age Associated Changes in Cardiac Function
1. Overall in systolic BP due to arterial stiffening & in plus wave velocity. Reflects resetting of the baro-receptor reflex to a higher level in the elderly
2. Myocardial contractility: relaxation is prolonged in senescent cardiac muscle due the sarcoplasmic reticulum SEQUESTERING less Ca+2
3. Ejection Fraction (EF): no change in resting EF
4. Heart Rate (HR): supine HR does not change, in sitting and standing positions DROPS from 10 to 25%.
![Page 11: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/11.jpg)
Aerobic Capacity & Cardiovascular Function During Exercise in the
ElderlyWith age, peak exercise capacity & peak oxygen consumption slightly but inter-individual
variation is substantial
Aerobic capacity 50% between 20 years to 80 years:
Maximal Cardiac Output (CO) 25% Peripheral O2 utilization 25% (due to
in muscle mass & strength)
Although the stroke volume in older persons is maintained, age apparently blunts the Frank-Starling mechanism
![Page 12: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/12.jpg)
Heart Failure: Cardiac Output (CO) insufficient to meet
physiologic demands
In the elderly, heart failure due to:• Mostly systemic arterial
hypertension• Coronary artery & valvular diseases
(due to impaired cardiac filling & chronic volume overload)
• Combined right & left cardiac failure most common, but isolated occurrence of left or right also
probable
![Page 13: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/13.jpg)
Heart Failure in the Elderly
• Symptoms: dyspnea, orthopnea, fatigue on exertion and dependent edema
• Severity: classified according to the NY Heart Association Scale
![Page 14: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/14.jpg)
The Cardiomyopathies:Myocardial disorders
without a known underlying cause BUT
where other heart diseases may coexist
Dilated CardiomyopathyHyperthrophic CardiomyopathyRestrictive
Cardiomyopathy
![Page 15: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/15.jpg)
Dilated Cardiomyopa
thy
Normal Heart
![Page 16: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/16.jpg)
Hypertrophic Cardiomyopathy
Normal Heart
![Page 17: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/17.jpg)
Restrictive Cardiomyopathy:
The classic example is the senile cardiac amyloidosis of the elderly, especially over 95 years old.
Normal Heart
![Page 18: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/18.jpg)
Cardiomyopathy: Any heart muscle disorder not caused by coronary artery disease, hypertension or
congenital valvular or pericardial diseases. Prevalence of heart failure:
25-54 yrs: 1%55-65 yrs: 3%65-74 yrs: 4.5%+75 yrs: 10%
• > 75% of patients with heart failure +60 years of age•Primary reason is Coronary Heart Disease (CHD)•Secondary reason is Hypertension•Third reason is cardiomyopathy
![Page 19: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/19.jpg)
Sudden Death• In young athletes (also in middle aged men), SUDDEN DEATH can occur in patients with congenital hypertrophic cardiomyopathy– Usually due to severe arrythmia (ventricular fibrillation)
– If diagnosis is made a cardiac defibrillator should be implanted.
• The SUDDEN DEATH of runners are usually limited to 1 case per 15,000 runners per year-- hence, very rare.
• MEMO: There is still the possibility of ANAPHYLACTIC SHOCK in runners or walkers, if stung by a bee.
![Page 20: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/20.jpg)
Syncope in ElderlyDefinition: temporary suspension of conciousness due to cerebral ischemia
Causes• Orthostatic Hypotension• Vaso-Vagal Reflex (?)• Arrhythmias (brady- & tachyarrhythmias)• Drugs
– Antihypertensives (vasodilators/diuretics)– Cardiac drugs: beta-blockers, digitalis, anti- arrhythmias, Ca+2 channel blockers, nitrates.
– Recreational: alcohol, marijuana and cocaine.
– Psychiatric: Antidepressants and phenothiazines
![Page 21: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/21.jpg)
Contributory Causes to Heart Failure in the Elderly
• Hypertension (poor elasticity of arterial system)
• Alcohol, but only if in excess• Viral infections• Autoimmunity• Heredity (specially for the cardiomyopathies)
• Senile amyloid• Diabetes (due to the microvascular disease)• Arrhythmias and especially the TACHYCARDIAS
![Page 22: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/22.jpg)
Conduction System in Aged Heart
• Sinoatrial Node: Increased fibrous tissue; seldom origin for arrythmias
• Atrio-Ventricular Node: Slight increase in collagen fibers
• Bundle of His: Increased fibrous tissue with higher frequency of First or Second degree heart block (the mobitz)
• Also the possibility of: L or R BBB (Bundle Branch Block) -this is seldom a complete heart block.
• In the conduction system fibrosis occurs: 40%– Coronary Artery Disease : 20%– Calcification : 10%
![Page 23: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/23.jpg)
Normal ECG
Ventricular Fibrillation
Atrial Fibrillation
![Page 24: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/24.jpg)
Aortic Stenosis:Narrowing of the aortic orifice of the heart
or of the aorta itself
A common condition due to:– Fatty alteration of collagen – Calcification – Rigidity and various degrees of aortic stenosis
– Amyloid infiltration of the valves
![Page 25: Aging of Cardiac Muscle and Cardiac Failure Dr. Franco Navazio](https://reader036.vdocuments.net/reader036/viewer/2022062714/56649d3f5503460f94a181d0/html5/thumbnails/25.jpg)
Age Specific Lesion: The Valves
• Fibrous thickening at sites of closure• Valvular sclerosis caused by collagen and elastic tissue, this is a true wear and tear phenomenon
• Calcification of the mitral ring where fatty degeneration invites deposition of calcium– Calcifications is detected in 17 to 45% of patients over 90 years of age
– Complications include: heart blocks, infections, embolic