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Hypermagnesemia and Hypomagnesemia

Hypermagnesaemia, Hypomagnesaemia, High and Low magnesium serum level

Magnesium (Magnesium, Mg²⁺)
Causes of Hypermagnesemia or Hypomagnesemia
ECG and Hypermagnesemia or Hypomagnesemia

Magnesium (Magnesium, Mg²⁺)

Is a co-factor for many enzymes (approximately 300)
Affects ion channels (for K⁺, Na⁺, Ca²⁺)

Secondary as well as action potential

Normal levels are: 0.8 - 1.0 mmol/l
Hypomagnesemia and hypokalemia

Hypomagnesemia causes

Increased potassium loss via the kidneys

Thus, hypomagnesemia leads to hypokalemia

Magnesium is mainly found in

Peas, beans, lentils

Causes of Hypermagnesemia or Hypomagnesemia

Most common causes of hypermagnesemia

Cell breakdown in the body (hemolysis, tumor lysis), magnesium is released into the blood from the broken-down cells
Kidney failure, leading to impaired secretion of magnesium into the urine

Most common causes of hypomagnesemia

Alcoholism - Alcoholism is associated with malnutrition (insufficient food intake). Alcohol stimulates the loss of magnesium via the kidneys
Diuretics - Stimulate the loss of magnesium via the kidneys
Diarrhea - Chronic diarrhea causes magnesium loss through the stool, e.g., in Crohn's disease, Ulcerative colitis
Severe acute pancreatitis - Released pancreatic enzymes break down fats into fatty acids, which form salts with magnesium. This decreases the level of free magnesium. A similar mechanism leads to hypocalcemia
Myocardial infarction - In the first 48 hours after myocardial infarction, up to 80% of patients have hypomagnesemia. During the infarction, catecholamines (adrenaline, noradrenaline) are released, causing magnesium to move into the intracellular space

ECG and Hypermagnesemia or Hypomagnesemia

ECG changes with magnesium imbalance

are very non-specific
often do not cause any ECG changes

ECG changes hypermagnesaemia, hypomagnesaemia, prolonged QT interval

Both Hyper- and Hypomagnesemia prolong the QT interval

There is an increased risk of developing Torsades de Pointes

In hypomagnesemia ( < 0.8 mmol/l ), non-specific ECG changes may occur:

Prolonged QT interval

Hypomagnesemia causes hypokalemia, which also prolongs the QT interval

Flattened T waves

In hypermagnesemia ( > 1 mmol/l ), non-specific ECG changes may occur:

ECG hypomagnesaemia 0,66mmmol/l, sinus tachycardia, prolonged QT interval

Hypomagnesemia (0.66 mmol/l)

Sinus Tachycardia

Heart Rate: 110/min.

Prolonged QT interval ( > 440ms)

QT interval 0.38s
Corrected (QT_C): 515ms

Prolonged QT interval, regardless of the cause, increases the risk of Torsades de Pointes

ECG hypermagnesaemia 1,18mmol/l, sinus bradycardia, first degree AV block, long QT interval

Hypermagnesemia (1.18 mmol/l)

Sinus Bradycardia (Heart Rate < 50/min.)

Heart Rate: 47/min.

AV Block I Degree

Prolonged PQ interval 0.32s ( > 0.2s)

In the case of AV block I degree and sinus bradycardia, consider:

Overdose of beta-blockers or calcium channel blockers
Inferior Wall Myocardial Infarction

ECG hypomagnesaemia, hypokalemia, long QT interval, U wave, r on t phanomenon, Torsades de Pointes (TdP)

Hypomagnesemia (0.7 mmol/l), Hypokalemia (1.9 mmol/l), and Torsades de Pointes

Prolonged QT (QU) interval ( > 0.44s)
Prolonged QT (QU) interval regardless of the cause increases the risk of Torsades de Pointes

This patient had severe hypokalemia with hypomagnesemia
Hypokalemia has a worse prognosis than hypomagnesemia

Hypokalemia

ST Depression (II, III, aVF)
Presence of U wave
Prolonged QT (QU) interval ( > 0.44s)

R on T phenomenon triggered malignant ventricular arrhythmia Torsades de Pointes

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

Home /

Hypermagnesemia and Hypomagnesemia

Hypermagnesaemia, Hypomagnesaemia, High and Low magnesium serum level

Magnesium (Magnesium, Mg²⁺)
Causes of Hypermagnesemia or Hypomagnesemia
ECG and Hypermagnesemia or Hypomagnesemia

Magnesium (Magnesium, Mg²⁺)

Is a co-factor for many enzymes (approximately 300)
Affects ion channels (for K⁺, Na⁺, Ca²⁺)

Secondary as well as action potential

Normal levels are: 0.8 - 1.0 mmol/l
Hypomagnesemia and hypokalemia

Hypomagnesemia causes

Increased potassium loss via the kidneys

Thus, hypomagnesemia leads to hypokalemia

Magnesium is mainly found in

Peas, beans, lentils

Causes of Hypermagnesemia or Hypomagnesemia

Most common causes of hypermagnesemia

Cell breakdown in the body (hemolysis, tumor lysis), magnesium is released into the blood from the broken-down cells
Kidney failure, leading to impaired secretion of magnesium into the urine

Most common causes of hypomagnesemia

Alcoholism - Alcoholism is associated with malnutrition (insufficient food intake). Alcohol stimulates the loss of magnesium via the kidneys
Diuretics - Stimulate the loss of magnesium via the kidneys
Diarrhea - Chronic diarrhea causes magnesium loss through the stool, e.g., in Crohn's disease, Ulcerative colitis
Severe acute pancreatitis - Released pancreatic enzymes break down fats into fatty acids, which form salts with magnesium. This decreases the level of free magnesium. A similar mechanism leads to hypocalcemia
Myocardial infarction - In the first 48 hours after myocardial infarction, up to 80% of patients have hypomagnesemia. During the infarction, catecholamines (adrenaline, noradrenaline) are released, causing magnesium to move into the intracellular space

ECG and Hypermagnesemia or Hypomagnesemia

ECG changes with magnesium imbalance

are very non-specific
often do not cause any ECG changes

Both Hyper- and Hypomagnesemia prolong the QT interval

There is an increased risk of developing Torsades de Pointes

In hypomagnesemia ( < 0.8 mmol/l ), non-specific ECG changes may occur:

Prolonged QT interval

Hypomagnesemia causes hypokalemia, which also prolongs the QT interval

Flattened T waves

In hypermagnesemia ( > 1 mmol/l ), non-specific ECG changes may occur:

Hypomagnesemia (0.66 mmol/l)

Sinus Tachycardia

Heart Rate: 110/min.

Prolonged QT interval ( > 440ms)

QT interval 0.38s
Corrected (QT_C): 515ms

Prolonged QT interval, regardless of the cause, increases the risk of Torsades de Pointes

Hypermagnesemia (1.18 mmol/l)

Sinus Bradycardia (Heart Rate < 50/min.)

Heart Rate: 47/min.

AV Block I Degree

Prolonged PQ interval 0.32s ( > 0.2s)

In the case of AV block I degree and sinus bradycardia, consider:

Overdose of beta-blockers or calcium channel blockers
Inferior Wall Myocardial Infarction

Hypomagnesemia (0.7 mmol/l), Hypokalemia (1.9 mmol/l), and Torsades de Pointes

Prolonged QT (QU) interval ( > 0.44s)
Prolonged QT (QU) interval regardless of the cause increases the risk of Torsades de Pointes

This patient had severe hypokalemia with hypomagnesemia
Hypokalemia has a worse prognosis than hypomagnesemia

Hypokalemia

ST Depression (II, III, aVF)
Presence of U wave
Prolonged QT (QU) interval ( > 0.44s)

R on T phenomenon triggered malignant ventricular arrhythmia Torsades de Pointes

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

Hypermagnesemia and Hypomagnesemia

Magnesium (Magnesium, Mg2+)

Causes of Hypermagnesemia or Hypomagnesemia

ECG and Hypermagnesemia or Hypomagnesemia

Hypermagnesemia and Hypomagnesemia

Magnesium (Magnesium, Mg2+)

Causes of Hypermagnesemia or Hypomagnesemia

ECG and Hypermagnesemia or Hypomagnesemia

Magnesium (Magnesium, Mg²⁺)

Magnesium (Magnesium, Mg²⁺)