What causes hypotension in inferior MI?
Up to 60% of patients with inferior wall acute myocardial infarction (AMI) develop hypotension. In many cases, profound hypotension is precipitated by the administration of nitroglycerin.
Can MI cause hypotension?
Some patients, particularly those with anterior MI, develop signs of end organ hypoperfusion in the setting of unsupported blood pressure measurements > 90 mm Hg. The urine output is typically low and the heart rate > 90 beats per minute.
Why is there hypotension in right ventricular infarction?
Diuretics and nitrates, which reduce preload, can diminish cardiac output and induce significant hypotension in the presence of right ventricular infarct.
Why does inferior wall MI cause bradycardia?
Also, because the right coronary artery perfuses the sinoatrial node, heart block and bradycardia may occur. A high degree heart block, defined as a second or third-degree block, is seen in 19% of patients with acute inferior wall MI. The amount of collateral circulation to the AV impacts the rate of heart blocks.
How do you treat hypotension in an MI with right ventricular involvement?
FIELD TREATMENT Fluid infusion is the mainstay of treatment for patients with RVI. In the case of an inferior MI with right ventricular involvement, the administration of nitroglycerin and morphine could cause an abrupt drop in blood pressure.
Why do nitrates cause hypotension?
The efficacy of nitrates is attributed to their vasodilator effects, especially their peripheral venodilating properties. A decrease in venous return and, to a certain extent, in arteriolar resistance usually causes hypotension of variable degrees.
Does myocardial infarction affect blood pressure?
In patients with myocardial infarction admitted within 6 hours from the onset of pain [57], 31.7% presented with elevated blood pressure (≥160/100 mm Hg): only 6.3% of these patients had elevated blood pressure levels after 6 hours, though not treated with any antihypertensive drug.
What happens to blood pressure during myocardial infarction?
During the first hour of admission 66 (31.7%) had a blood pressure recorded 160/100 or greater. By the sixth hour, without specific antihypertensive therapy, this number had fallen to 13 (6.3%). This fall was subsequently maintained with very similar trends for both acute myocardial infarction and cardiac ischemia.
When a patient presents with an inferior wall MI What other area of the heart is at risk?
While inferior wall MIs traditionally have a good prognosis, there are a few factors that may increase mortality. Approximately 40% of inferior wall infarctions also involve the right ventricle. Right ventricular infarctions are very pre-load dependent, and nitrates may precipitate a drop in blood pressure.
Does MI cause tachycardia or bradycardia?
Abstract. The most common arrhythmias associated with inferior-wall and anterior-wall myocardial infarction are bradycardia and supraventricular and ventricular tachycardia.
Why nitrates are contraindicated in inferior wall MI?
Nitroglycerin is also contraindicated in the setting of an inferior MI with right ventricular involvement because, in this specific situation, the heart is dependent on preload.
Does nitroglycerin cause hypotension?
Nitroglycerin (NTG) may cause paradoxical bradycardia and occasional life-threatening hypotension.
How does pain affect blood pressure and heart rate?
During pain outbreaks, there is a release of adrenalin which elevates heart rate and blood pressure. This can lead to severe cardiac episodes, stroke or even death. In some chronic pain patients, long-term pain can produce chronic tachycardia—a pulse rate greater than 100 heart beats per minute.
What are the symptoms of inferior myocardial infarction?
Symptoms include chest pain, heaviness or pressure and shortness of breath, and diaphoresis with radiation to the jaw or arms. There are often other symptoms such as fatigue, lightheadedness, or nausea. On physical exam, particular attention should be given to the heart rate since bradycardia and heart block may occur.
What is affected in an inferior MI?
Inferior wall myocardial infarction (MI) occurs from a coronary artery occlusion with resultant decreased perfusion to that region of the myocardium. Unless there is timely treatment, this results in myocardial ischemia followed by infarction.
Why do you not give Nitro to inferior MI?
Which artery is blocked in inferior wall MI?
Acute inferior wall myocardial infarction is usually due to occlusion of the RCA and is rarely due to occlusion of LCX.