Vernakalant is a new antiarrhythmic drug that acts selectively in the atrium, targeting atrial specific channels. Vernakalant is an anti-arrhythmic medicine that acts preferentially in the atria by prolonging atrial refractoriness and by rate-dependently slowing impulse conduction. These anti-fibrillatory actions on refractoriness and conduction are thought to suppress reentry, and are potentiated in the atria during atrial fibrillation. The preferential effects of vernakalant on the atria are postulated to result from its block of currents that are expressed in the atria (e.g., the ultra-rapid delayed rectifier potassium current; and the acetylcholine-activated potassium current), but not in the ventricles, as well as the unique electrophysiologic condition of the fibrillating atria. An oral formulation of vernakalant is in phase II development as a long-term maintenance therapy for patients with atrial fibrillation. An intravenous formulation of vernakalant has been launched in most countries in Europe and Latin America, and in Hong Kong, for the acute conversion of atrial fibrillation. The product has been approved for the acute conversion of atrial fibrillation in South Africa, Iceland, Turkey and is awaiting approval for the same indication in Canada. Phase III development of the IV formulation is ongoing at sites in Asia, and development is currently on hold in the US.

Cibenzoline is a class I sodium channel blocker antiarrhythmic drug available in a limited number of countries. Cibenzoline also has moderate calcium channel blocking (class IV) effects and prolongs the action potential duration through its potassium channel blocking (class III) effect. It is used for the treatment of supraventricular and ventricular arrhythmias, and in obstructive hypertrophic cardiomyopathy.

Proscillaridin is a substance that was used in Europe for the treatment of heart failure and atrial fibrillation. Proscillaridin belongs to glycosides and acts as a Na+/K+-ATPase inhibitor.

Hexobendine (Ustimon or ST7090) is a vasodilator. It inhibits uptake of adenosine and cAMP. Hexobendine was investigated in clinical trials for the treatment of cerebrovascular and coronary artery diseases.

Bucladesine is a cyclic nucleotide derivative which mimics the action of endogenous cAMP and is a phosphodiesterase inhibitor. The compound is used in a wide variety of research applications because it mimics cAMP and can induce normal physiological responses when added to cells in experimental conditions. cAMP is only able to elicit minimal responses in these situations. The neurite outgrowth instigated by bucladesine in cell cultures has been shown to be enhanced by nardosinone. Recently, the effect of bucladesine as a cAMP analog has been studied on the pentylenetetrazol-induced seizure in the wild-type mice. The data showed that bucladesine (300nM/mouse) reduced the seizure latency and threshold. In addition they found that combination of bucladesine and pentoxyfillin has additive effect on seizure latency and threshold. Bucladesine is more lipophilic than cAMP and in contrast to cAMP capable of penetrating cell membranes. Bucladesine interferes with different protein kinases which are normally activated by cAMP. Bucladesine has undergone in the past clinical developments as systemic treatment for cardioprotection and as topical treatment to improve wound healing. In Japan, a bucladesine ointment (Actosin® ointment; Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan) was marketed to treat skin ulcers. Clinical studies have shown favourable effects on diabetic foot ulcers or decubitus, but the compound was later withdrawn despite good tolerability. One possible reason for the withdrawal may be the odour of the cream formulation which can be related to the hydrolytic cleavage in aqueous solutions resulting in release of butyric acid.

Nicorandil is a derivative of the niacinamide that is structurally combined with an organic nitrate. It provides a dual mode of action leading to relaxation of vascular smooth muscle. Nicorandil is a potassium-channel opener that causes vasodilatation of arterioles and large coronary arteries. Its nitrate-like properties produce venous vasodilation through stimulation of guanylate cyclase. Nicorandil has a direct effect on coronary arteries without leading to a steal phenomenon. The overall action improves blood flow to post-stenotic regions and the oxygen balance in the myocardium.

Ajmaline, (also known by trade names Gilurytmal, Ritmos, and Aritmina) is an alkaloid found in the root of Rauwolfia serpentina, among other plant sources. It is a class Ia antiarrhythmic agent that apparently acts by changing the shape and threshold of cardiac action potentials. The class I antiarrhythmic agents interfere with the sodium channel. A class IA agent lengthens the action potential (right shift) which brings about improvement in abnormal heart rhythms. This drug in particular has a high affinity for the Nav 1.5 sodium channel. Ajmaline produces potent sodium channel blocking effects and a very short half-life which makes it a very useful drug for acute intravenous treatments. The drug has been very popular in some countries for the treatment of atrial fibrillation in patients with the Wolff–Parkinson–White syndrome and in well tolerated monomorphic ventricular tachycardias. It has also been used for many years as a drug to challenge the conduction system of the heart in cases of bundle branch block and syncope. In these cases, abnormal prolongation of the HV interval has been taken as a proof for infrahisian conduction defects tributary for permanent pacemaker implantation. Ajmaline is used as an antiarrhythmic agent.

Erythrityl Tetranitrate is a vasodilator indicated for the prevention of angina. Sold under the brand name Cardilate, Erythrityl Tetranitrate is used for the prophylaxis and long-term treatment of patients with frequent or recurrent anginal pain or coronary insufficiency and during the postcoronary convalescent period to hasten recovery. Similar to other nitrites and organic nitrates, erythrityl tetranitrate is converted to an active intermediate compound which activates the enzyme guanylate cyclase. This stimulates the synthesis of cyclic guanosine 3',5'-monophosphate (cGMP) which then activates a series of protein kinase-dependent phosphorylations in the smooth muscle cells, eventually resulting in the dephosphorylation of the myosin light chain of the smooth muscle fiber. The subsequent release of calcium ions results in the relaxation of the smooth muscle cells and vasodilation. Erythrityl Tetranitrate is a is an atrial natriuretic peptide receptor agonist. Erythrityl tetranitrate is a physiologically effective long-acting agent in patients with coronary heart disease.

Angiotensin is a peptide hormone that causes vasoconstriction and a subsequent increase in blood pressure. It is part of the renin-angiotensin system, which is a major target for drugs that lower blood pressure. Angiotensin also stimulates the release of aldosterone, another hormone, from the adrenal cortex. Aldosterone promotes sodium retention in the distal nephron, in the kidney, which also drives blood pressure up. Angiotensin is an oligopeptide and is a hormone and a powerful dipsogen. Angiotensin I is derived from the precursor molecule angiotensinogen, a serum globulin produced in the liver. Angiotensin I is converted to angiotensin II (AII) through removal of two C-terminal residues by the enzyme angiotensin-converting enzyme (ACE), primarily through ACE within the lung (but also present in endothelial cells and kidney epithelial cells). ACE found in other tissues of the body has no physiological role (ACE has a high density in the lung, but activation here promotes no vasoconstriction, angiotensin II is below physiological levels of action). Angiotensin II acts as an endocrine, autocrine/paracrine, and intracrine hormone. Angiotensin II has prothrombotic potential through adhesion and aggregation of platelets and stimulation of PAI-1 and PAI-2. When cardiac cell growth is stimulated, a local (autocrine-paracrine) renin-angiotensin system is activated in the cardiac myocyte, which stimulates cardiac cell growth through protein kinase C. The same system can be activated in smooth muscle cells in conditions of hypertension, atherosclerosis, or endothelial damage. Angiotensin II is the most important Gq stimulator of the heart during hypertrophy, compared to endothelin-1 and α1 adrenoreceptors. Angiotensin II increases thirst sensation (dipsogen) through the subfornical organ of the brain, decreases the response of the baroreceptor reflex, and increases the desire for salt. It increases secretion of ADH in the posterior pituitary and secretion of ACTH in the anterior pituitary. It also potentiates the release of norepinephrine by direct action on postganglionic sympathetic fibers. Angiotensin II acts on the adrenal cortex, causing it to release aldosterone, a hormone that causes the kidneys to retain sodium and lose potassium. Elevated plasma angiotensin II levels are responsible for the elevated aldosterone levels present during the luteal phase of the menstrual cycle. Angiotensin II has a direct effect on the proximal tubules to increase Na+ reabsorption. It has a complex and variable effect on glomerular filtration and renal blood flow depending on the setting. Increases in systemic blood pressure will maintain renal perfusion pressure; however, constriction of the afferent and efferent glomerular arterioles will tend to restrict renal blood flow. The effect on the efferent arteriolar resistance is, however, markedly greater, in part due to its smaller basal diameter; this tends to increase glomerular capillary hydrostatic pressure and maintain glomerular filtration rate. A number of other mechanisms can affect renal blood flow and GFR. High concentrations of Angiotensin II can constrict the glomerular mesangium, reducing the area for glomerular filtration. Angiotensin II is a sensitizer to tubuloglomerular feedback, preventing an excessive rise in GFR. Angiotensin II causes the local release of prostaglandins, which, in turn, antagonize renal vasoconstriction. The net effect of these competing mechanisms on glomerular filtration will vary with the physiological and pharmacological environment. Angiotensin was independently isolated in Indianapolis and Argentina in the late 1930s (as 'angiotonin' and 'hypertensin', respectively) and subsequently characterised and synthesized by groups at the Cleveland Clinic and Ciba laboratories in Basel, Switzerland.