Heart attacks & detection
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Transcript of Heart attacks & detection
Heart Attacks & Detection
Heart Attacks & Detection
ABHISEK ANAND
A simple definition of a heart attack is a sudden failure of the heart resulting from an occlusion or obstruction of a coronary artery.
SIGNS AND SYMPTOMS
Pressure, a feeling of fullness or a squeezing pain in the center of your chest that lasts for more than a few minutes
Pain extending beyond your chest to your shoulder, arm, back, or even to your teeth and jaw
Increasing episodes of chest pain
Prolonged pain in the upper abdomen
Shortness of breath
Sweating
Impending sense of doom
Fainting
Nausea and vomiting
Risk factors
Age.
Tobacco.
Diabetes.
High blood pressure.
High blood cholesterol or triglyceride levels.
Family history of heart attack.
Lack of physical activity.
Obesity.
Stress.
Illegal drug use.
Gender
High blood pressure
Alcohol
Oral contraceptive pill
COMPLICATIONS
Abnormal heart rhythms
Heart failure.
Heart rupture.
Valve problems.
Tests and diagnosis
Electrocardiogram (ECG).
Blood tests
Echocardiography ("echo")
Cardiovascular magnetic resonance imaging (CMR)
Cardiac stress test
Auscultation
Holter monitor
Electrophysiology study
Sphygmomanometer
Cardiac marker
Coronary catheterization
Fractional flow reserve (FFRmyo)
Intravascular ultrasound (IVUS)
Optical coherence tomography (OCT)
Electrocardiography (ECG or EKG)
Concepts of the electrocardiography
ABHISEK ANAND
C.T.I.T SHAHPUR JALANDHAR
WHAT IS AN ECG & EKG
Allows for detection of
conduction abnormalities
Helpful with non-cardiac
diseases (e.g. pulmonary embolism or hypothermia)
Helps detect electrolyte disturbances (hyper- & hypokalemia)
A recording of the electrical activity of the heart over time.
The ECG Paper
Horizontally
One small box - 0.04 s
One large box - 0.20 s
Vertically
One large box - 0.5 mV
Recall Heart Physiology !
SA node
(Sinoatrial node)
AV Junction
( Atrioventricular (AV) junction)
His-Purkinje
Myocardial cells
Electrical potential
Autonomic Nervous system
Myocardial Cells
Action potential
Depolarization
Repolarization
Critical electrolytes
Sodium, potassium, calcium
Excitability
MAJOR CHANNELS
Standard Limb Leads
Lead Placement
Precordial Leads
Summary of Leads
Limb LeadsPrecordial LeadsBipolarI, II, III(standard limb leads)-UnipolaraVR, aVL, aVF (augmented limb leads)V1-V6Electrophysiology
A transmembrane electrical gradient (potential) is maintained, with the interior of the cell negative with respect to outside the cell
(-90mv) and (+30mv) inside and outside the cell
Caused by unequal distribution of ions inside vs. outside cell
Na+ higher outside than inside cell
Ca+ much higher
K+ higher inside cell than outside
Maintenance by ion selective channels, active pumps and exchangers
Waveforms
Depolarization of artria
Depolarization of ventricals
Repolarization of the ventricals
Repolarization of purkinje fiber
Cardiac Action Potential
Divided into five phases (0,1,2,3,4)
Phase 0 opening of fast Na channels and rapid
depolarization
Drives Na+ into cell (inward current),
changing membrane potential
Transient outward current due to movement
of Cl- and K+
Phase 1 initial rapid repolarization
Closure of the fast Na+ channels
Phase 0 and 1 together correspond to the R and S waves of the ECG
Cardiac Action Potential
Phase 2 - plateau phase
sustained by the balance between the inward movement of Ca+ and outward movement of K+
Has a long duration compared to other nerve and muscle tissue
Normally blocks any premature stimulator signals (other muscle tissue can accept additional stimulation and increase contractility in a summation effect)
Corresponds to ST segment of the ECG.
Phase 3 repolarization
K+ channels remain open,
Allows K+ to build up outside the cell, causing the cell to repolarize
K + channels finally close when membrane potential reaches certain level
Corresponds to T wave on the ECG
Cardiac Action Potential.
Phase 4 - resting phase (restingmembrane potential)
At (-90mv) stable
Phase cardiac cells remain in until stimulated
Associated with diastole portion of heart cycle
Summary of ionic basis
26
Cardiac action potential in relation with ECG
R
S
T
summary
Introduction to EchocardiographyCardiac Ultrasound
Generation Of An Ultrasound Image
Echocardiography (echo or echocardiogram) is a type of ultrasound test that uses high-pitched sound waves to produce an image of the heart. The sound waves are sent through a device called a transducer and are reflected off the various structures of the heart. These echoes are converted into pictures of the heart that can be seen on a video monitor.There is no special preparation for the test.
Ultrasound gel is applied to the transducer to allow transmission of the sound waves from the transducer to the skin
The transducer transforms the echo (mechanical energy) into an electrical signal which is processed and displayed as an image on the screen.
The conversion of sound to electrical energy is called the piezoelectric effect
Machines
There are 5 basic components of an ultrasound scanner that are required for generation, display and storage of an ultrasound image.
Pulse generator - applies high amplitude voltage to energize the crystals
Transducer - converts electrical energy to mechanical (ultrasound) energy and vice versa
Receiver - detects and amplifies weak signals
Display - displays ultrasound signals in a variety of modes
Memory - stores video display
Cardiovascular magnetic resonance imaging (CMR)
sometimes known as cardiac MRI, is a medical imaging technology for the non-invasive assessment of the function and structure of the cardiovascular system. It is derived from and based on the same basic principles as magnetic resonance imaging (MRI) but with optimization for use in the cardiovascular system. These optimizations are principally in the use of ECG gating and rapid imaging techniques or sequences. By combining a variety of such techniques into protocols, key functional and morphological features of the cardiovascular system can be assessed.
Cardiac stress test
A cardiac stress test with Myocardial Perfusion Imaging (MPI) is a non-invasive test (no
surgery or cutting skin). This test takes four (4) hours and is done in three (3) parts with
breaks between each part. A cardiac stress test with MPI is done to study the blood flow
to your heart during stress and at rest. This test helps your doctor diagnose coronary
artery disease (CAD).
Auscultation: Listening to breath sounds with a stethoscope
What are heart sounds?
Heart sounds are generated by the beating heart and the resultant flow of blood through the cardiac circulation, also referred to as the heartbeat. In cardiac auscultation, the nurse uses a stethoscope to listen for normal heart sounds and any other adventitious sounds or murmurs that may be present.
In healthy adults, there are two normal heart sounds often described as a lub and a dub (or dup), that occur in sequence with each heart beat. These are the first heart sound (S1) and the second heart sound (S2), produced by the closing of the atrioventricular valves (tricuspid and mitral valves ) and the semilunar valves (pulmonic and aortic) respectively.
Auscultation Techniques
AUSCULTATION OF THE HEART
be sure to use both sides of the stethoscope to examine the heart
the diaphragm is best for hearing high-pitched sounds, including S1, S2 and most heart murmurs
the bell is bests for hearing low-pitched sounds, including S3, S4 and a few murmurs (e.g. mitral stenosis)
use LIGHT TOUCH when using the bell. Pressure turns it into a diaphragm
Cardiac Biomarkers
A biomarker is a substance used as an indicator of a biologic state. It is a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.
Cardiac markers are substances released from heart muscle when it is damaged as a result of myocardial infarction.
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