Acute attacks During acute attacks, individuals typically respond well to fast-acting sublingual, intravenous, or spray nitroglycerin formulations. The onset of symptom relief in response to intravenous administration, which is used in more severe attacks of<unk> , occurs almost immediately while sublingual formulations of it act within 1–5 minutes. Spray formulations also require ~1–5 minutes to act. Maintenance As maintenance therapy, sublingual nitroglycerin tablets can be taken 3-5 min before conducting activity that causes<unk>  by the small percentage of patients who experience<unk>  infrequently and only when doing such activity. For most afflicted individuals, antianginals are used as maintenance therapy to avoid attacks of<unk> . Calcium channel blockers of the dihydropyridine class (e.g. nifedipine, amlodipine) or non-dihydropyridine class (e.g. verapamil, diltiazem) are regarded as first-line drugs to avoid<unk>  attacks. Long-acting nitroglycerins such as isosorbide dinitrate or intermittent use of short-acting nitroglycerin (to treat acute symptoms) may be added to the calcium channel blocker regimen in individuals responding sub-optimally to the channel blockers. However, individuals commonly develop tolerance, i.e. resistance, to the efficacy of continuously used long-acting nitroglycerin formulations. One strategy to avoid this development is to schedule nitroglycerin-free periods of between 12 and 14 hours between doses of long-acting nitroglycerin formulations. Individuals whose symptoms are poorly controlled by a calcium blocker may benefit from addition of a long-acting nitroglycerin and/or a second calcium channel blocker of a different class than the blocker already in use. Nevertheless, about 20% of individuals fail to respond adequately to the two-drug calcium blocker plus long-acting nitroglycerin regimen. If these individuals have significant permanent occlusion of their coronary arteries, they may benefit by stenting their occluded arteries. However, coronary stenting is contraindicated in drug- refractory individuals who do not have significant organic occlusion of their coronary arteries. For the latter individuals, other, less fully investigated drugs may provide symptom relief. Statins, e.g. fluvastatin, while not evaluated in large-scale double-blind studies, are reportedly helpful in reducing<unk>  attacks and should be considered in patients when calcium channel blockers and nitroglycerin fail to achieve good results. There is also interest in using rho-kinase inhibitors, such as fasudil (available in Japan and China but not the USA), and blocker of alpha-1 adrenergic receptors such as prazosin (which when activated cause<unk> sodilation) but studies are needed to support their clinical utility in<unk> . Emergency Individuals with certain severe complications of<unk>  require immediate therapy. Individuals presenting with potentially lethal irregularities in the rhythm of their heart beating or a history of episodic fainting spells due to such arrhythmias require implantation of an internal defibrillator and/or cardiac pacemaker to stop such arrhythmias and restore normal heart beating. Other rare but severe complications of<unk>  viz., myocardial infarction, severe congestive heart failure, and cardiogenic shock require the same immediate medical interventions that are used for other causes of these extremis conditions. In all of these emergency cases, percutaneous coronary intervention to stent areas where coronary arteries evidence spasm is only useful in individuals who have concomitant coronary atherosclerosis on coronary angiogram.
Variant angina
Microvascular angina
Unstable angina
Coronary steal
Bundle branch block
Atopy
Palisade 
Renal angina