We share these clinical tips below and hope they will be helpful to you.
1. First clarify hyperthyroid heart disease combined with heart failure
Just like giving punishment to a prisoner, you have to convict him first before you can wrongly accuse a good person.
Before starting anti-hyperthyroid heart disease combined with heart failure treatment, it is necessary to clarify whether the diagnosis of hyperthyroid heart disease is established and exclude other heart diseases, but it is necessary to pay attention to the possibility that other diseases can be combined at the same time.
2. Which beta-blocker to choose
Studies have confirmed that among many beta-blockers, propranolol has the effect of blocking the conversion of T4 to T3, and can counteract the effect of catecholamines, thus rapidly relieving the symptoms of hyperthyroidism such as tachycardia, eye and face cramps, tremor and anxiety, and these effects are strongest with propranolol.
Atenolol and metoprolol can also mildly reduce T3 levels, but are generally not used as long-term and stand-alone medications for hyperthyroidism.
3. Controversies in the use of propranolol
A few people and a few textbooks list the use of propranolol as a contraindication to the treatment of hyperthyroidism, but unfortunately do not state the specific reasons why propranolol use is contraindicated. This view may be based on several considerations.
One is that the use of probenecid is generally not advocated in the setting of acute heart failure episodes.
The second is that probenecid may induce or aggravate acute heart failure in hyperthyroid heart disease.
However, most scholars and most textbooks and monographs advocate the appropriate use of propranolol in hyperthyroidism combined with heart failure. The reason for this is that the continued and excessive activation of the adrenergic receptor pathway in systolic heart failure is harmful to the heart. The concentration of norepinephrine in the failing heart is sufficient to produce cardiomyocyte damage and the activation of the chronic adrenergic system mediates myocardial remodeling, which is the main pathophysiological mechanism for the development of heart failure, which is the basis for the application of beta-blockers in the treatment of chronic heart failure. The main reason is that propranolol can block catecholamine-like effects and reduce the toxic effects of thyroxine on the heart. In addition, propranolol can also inhibit the conversion of T4 to T3, which plays a better role in controlling heart rate.
Clinical trials have shown that although propranolol has a significant inhibitory effect on cardiac function at the beginning of treatment and LVEF is reduced. However, if the dose is gradually increased from a small dose, the inhibitory effect is not obvious, and long-term treatment (>3 months) can improve cardiac function and increase LVEF. Treatment for 4-12 months reduces ventricular muscle weight and volume and improves ventricular shape, suggesting delayed or reversed myocardial remodeling.
Therefore, the notion that the use of pranolol is contraindicated in hyperthyroidism combined with heart failure should be dispelled.
4. How to deal with hyperthyroidism combined with congestive heart failure
(1) In general, the treatment of hyperthyroidism combined with heart failure has become more difficult to correct. In terms of the use of probenecid, the use of probenecid in hyperthyroidism combined with heart failure needs to be cautious but not contraindicated.
(2) In acute attacks of heart failure, weighing the pros and cons, if there is an urgent need to use Prenalol, it is necessary to control the acute heart failure first or simultaneously with digitalis preparations.
(3) When hyperthyroid heart disease is combined with heart failure, the sensitivity to digoxin is reduced, and the dose can be increased rather than reduced when using it (Chinese guidelines for the diagnosis and treatment of thyroid disease).
5.Iodine 131 treatment
After heart failure is controlled, control hyperthyroidism as early as possible. Iodine 131 therapy is recommended, and long-term treatment with anti-hyperthyroid drugs is not recommended.