Does ischemia cause hyperkalemia?

Hyperkalemia can be systemic or interstitial (confined to cardiac or other tissue as a result of acute global or regional ischemia).

How does hypokalemia and hyperkalemia affect the heart?

If left untreated, both severe hypokalemia and severe hyperkalemia can lead to paralysis, cardiac arrhythmias, and cardiac arrest. Hyperkalemia, generally carries a higher risk of morbidity and mortality if left untreated. Severe hypokalemia may also cause respiratory failure, constipation and ileus.

What causes hypokalemia and hyperkalemia?

Hypokalemia and hyperkalemia are common electrolyte disorders caused by changes in potassium intake, altered excretion, or transcellular shifts. Diuretic use and gastrointestinal losses are common causes of hypokalemia, whereas kidney disease, hyperglycemia, and medication use are common causes of hyperkalemia.

Can myocardial infarction cause hyperkalemia?

Conclusions: Hyperkalemia is common in patients who are hospitalized with acute myocardial infarction. Higher maximum potassium levels and number of hyperkalemic events are associated with a steep mortality increase, with higher risks for adverse outcomes observed even at mild levels of hyperkalemia.

Why does hypokalemia cause ventricular tachycardia?

The prolongation of ventricular repolarization in hypokalemic setting is caused by inhibition of outward potassium currents and often associated with increased propensity for early afterdepolarizations. Slowed conduction is attributed to membrane hyperpolarization and increased excitation threshold.

Which is worse hypokalemia or hyperkalemia?

Although it is much less common than hypokalemia, hyperkalemia is much more dangerous, and when unrecognized or untreated it may result in cardiac arrest.

Does hypokalemia cause myocardial infarction?

Also in hypertension, thiazide diuretics increased ectopic ventricular activity during exercise (17). In myocardial infarction, hypokalemia was associated with an increased risk of ventricular tachycardia and ventricular fibrillation.

How does hypokalemia affect cardiac output?

The most dangerous aspect of hypokalemia is the risk of ECG changes (QT prolongation, appearance of U waves that may mimic atrial flutter, T-wave flattening, or ST-segment depression) resulting in potentially lethal cardiac dysrhythmia.

How does hyperkalemia cause cardiac arrhythmia?

Mechanism of cardiac arrhythmia in hyperkalemia. In normokalemia, the cell membrane of the cardiomyocyte is polarized (resting potential around −90 mV). In moderate hyperkalemia, the cell membrane becomes partially depolarized, bringing the resting potential closer to the threshold potential for AP initiation.

Does hyperkalemia cause bradycardia or tachycardia?

While less common than hypokalemia, hyperkalemia is often more dangerous and is associated with potentially lethal dysrhythmias such as ventricular tachycardia and ventricular fibrillation. Additional rhythm changes related to hyper- kalemia are sinus bradycardia, sinus arrest, and slow idioventricular rhythms.