钙通道阻滞剂是一大类广泛用于治疗心血管疾病的药物。They are most commonly used today as a first-line treatment for高血压病，but they are also effective in treating心绞痛，室上性心动过速，和肥厚性心肌病.In general,the calcium channel blockers are well-tolerated,but there are certain side effects that need to be watched out for.
Calcium channel blockers prevent calcium from entering into the heart muscle cells,and into the smooth muscle cells that cause blood vessels to constrict.通过减少钙的流入，calcium channel blockers cause these muscle cells to "relax." This relaxing effect results in the dilation of blood vessels,心脏肌肉收缩力降低。
All the effects of calcium blockers (blood vessel dilation,减少心肌收缩，降低心肌所需的氧气量。
减少心脏供氧量有助于预防心脏病ischemia（缺氧）even when blood flow through the冠状动脉被一个动脉粥样硬化斑块.在那些有稳定型心绞痛，calcium blockers usually increase the amount of exercise they can perform before they experience angina.Calcium blockers can be especially useful in people withPrinzmetal's angina (coronary artery spasm)since they can directly reduce spasm of the coronary arteries.
市场上有很多钙阻滞剂，它们并不都是一样的。There are three general types of widely used calcium blockers:
1) The dihydropyridines. The drugs nifedipine (Procardia,阿达拉特）nicardipine (Cardene),非洛地平and amlodipine (Norvasc),称为二氢吡啶。These drugs cause significant dilation of blood vessels and relatively little effect on the heart muscle and heart rate.They are most useful for treating hypertension.
2）维拉帕米.维拉帕米CoveraIsoptin,Verelan) affects the heart muscle and is particularly effective in slowing the heart rate,但对血管影响不大。对高血压不太有用，但对心绞痛和心律失常很好。
心绞痛:所有的钙阻滞剂都被用于治疗心绞痛。However,the most commonly used for this purpose are the longer-acting forms of diltiazem and verapamil,amlodipine,或非洛地平。
Nifedipine尤其是其短小的表演形式，should generally be avoided in people with angina since the pronounced blood vessel dilation produced by this drug can increase in adrenaline,导致心率更快，and consequently an increase in cardiac oxygen requirements.因此，短效硝苯地平实际上可以恶化心肌缺血。
Supraventricular arrhythmias:Calcium blockers (especially verapamil) partially blocks the function of the AV node and therefore is often quite useful in treating the supraventricular arrhythmias that rely on the AV node in order to persist.特别地，房室结折返性心动过速（最常见的一种室上性心律失常）通常可以通过维拉帕米治疗来控制。
Hypertrophic cardiomyopathy:Calcium blockers can be used to help reduce the "stiffness" of the left ventricle in people with hypertrophic cardiomyopathy,and in this way can reduce symptoms.
Common most side effects of the dihydropyridine group of calcium channel blockers include headache,头晕，flushing,脚和脚踝肿胀。
维拉帕米和地尔硫卓最常见的副作用是便秘，which can occur in up to 25% of people treated with these drugs.These non-dihydropyridine calcium blockers can also cause bradycardia (slow heart rate),而且，because they reduce the force of contraction of the heart muscle,they can lower the cardiac output.如果患者患有heart failure.
钙通道阻滞剂广泛用于治疗各种心血管疾病。虽然他们通常都能被很好地容忍，precautions need to be taken to avoid potentially serious side effects.