Case Study Assignment - ECG

RUNNING HEAD: CASE STUDY ASSIGNMENT - ECG
CASE STUDY ASSIGNMENT - ECG
Name of Student
Name of University
Author note

1CASE STUDY ASSIGNMENT - ECG
Table of Contents
Response to question 1:..............................................................................................................2
Response to Question 2:.............................................................................................................3
Response to Question 3:.............................................................................................................5
References:.................................................................................................................................9

2CASE STUDY ASSIGNMENT - ECG
Response to question 1:
The electrocardiogram of Alan reveals a typical graph with coronary ischemic
deviations mediated electrophysiology which are described in terms of its biophysical
properties. The electrical properties are altered making the resting membrane potential
negative in phase 4 and action potential’s duration is diminished to less than about 200
milliseconds, with alteration of phase 2. Consequently, there forms a voltage gradient existing
between the ischemic and normal myocytes. These biophysical changes are then recorded by
electrocardiogram in form ST segment deviations from isoelectric point. Any change in the
resting membrane potential creates ST depression during diastole, contributing to the ST
elevation on the ECG (Azoz et al., 2018). A shorter action potential marks an abnormal flow
of current during systole (in trans-mural ischemia). Direction of the ST vector towards
positive outer epicardial zones produces tall T-waves and ST elevations. Amplitude of the ST
elevation indicates a severity of the ischemia. If a marked ST depression or elevation is
observed in a range of multiple leads, it should be considered that ischemia has affected a
broader area of the myocardium. Generally, in the ST elevation area – a new elevation is seen
at J point within two of the contiguous leads that is with cut-points about more than 0.1
millivolts in all the ECG leads except the V2-V3 leads. In the leads V2-V3, cut-points are
found to be greater than (and sometimes equal) to 0.2 millivolts in the affected men who are
more than 40 years old. The reading is greater than (equal to) 0.25 millivolts in affected men
who are somewhat less than 40 years and it is greater than 0.15 millivolts in affected women.
For a T wave and ST depression changes – a new horizontal is seen with downward sloping
of the ST depression is found to be greater than (or sometimes equal to) 0.05 millivolts in two
of the ECG leads. And T wave inversion is greater than or sometimes equal to around 0.1
millivolts in the two contiguous ECG leads showing a prominently represented R wave and
R/S ratio whose value greater than the value of 1.

3CASE STUDY ASSIGNMENT - ECG
Coronary artery results from an accumulation of plaque in the arterial walls of
coronary arteries supplying the walls of the heart. Plaque comprises of cholesterol deposits
and other molecules occluding the artery (Mandell et al., 2017). Plaque buildup narrows the
arteries over time, which results in total or partial blockade to the blood flow by a process
called atherosclerosis. Excessive plaque causes severe narrowing of the coronary artery
lumen obstructing blood flow greatly in the myocardial walls, lessening oxygen perfusion
causing ischemia (Elumalai and Sujitha, 2016). Myocardial ischemia is responsible for
different kinds of angina – stable, unstable and prinzmetal angina which less commonly leads
to shortness of breath (dyspnea) secondary to dysfunctional left ventricular and cardiac
arrhythmias. The mechanisms of myocardial ischemia is related with chronic coronary
insufficiency plus symptoms of stable angina (Ohman, 2016). Oxygen delivery to walls of
myocardium is proportional to oxygen transport in the blood along with the viscosity of
coronary blood flow. Oxygen transport of blood can well be disrupted readily by a sudden
and rapid fall in levels of hemoglobin. This can suddenly worsen the angina symptoms in the
patient with a history of stable angina for many years and associated anemia (Miyamoto et
al., 2015). Generally, atherosclerosis of the non-resistance coronaries of epicardium (1.5–4
mm) can have an effect by distortion of the arterial physiology while it introduces a
resistance to the established coronary flow. Newly acquired resistance have a great impact on
the reserve of coronary flow leading to reduction of sufficient levels of oxygen delivery to the
myocardium (Alderman et al., 2016).
Response to Question 2:
The medications used in the emergency department, to treat Alan’s symptoms are
glyceryl tri-nitrate, morphine and aspirin.