Sexual dysfunction refers to a problem during any phase of the sexual response cycle that prevents the individual or couple from experiencing satisfaction from the sexual activity. The sexual response cycle has four phases: excitement, plateau, orgasm, and resolution. Sexual dysfunction can be caused by physical and emotional factors, or a combination of both. The side effects of some medications also can lead to sexual dysfunction.
Abstract | Full Text | Full Text PDF | PubMed | Scopus (95) | Google ScholarSee all References Another contraindication is the use of recreational drugs (“poppers”) that contain amyl nitrate. The guidelines also caution use in patients who have a high risk of cardiovascular effects, including patients with active coronary artery disease who are not taking nitrates, patients with congestive heart failure with a borderline low blood pressure level and low blood volume, or those with complicated multidrug antihypertensive regimens.
Crossref | PubMed | Scopus (72) | Google ScholarSee all References This study found that the mean PSV was a better predictor of the presence of cardiovascular disease than stratification by standard cardiac risk factors such as diabetes mellitus, hypertension, obesity, and smoking. The researchers recommended that persons with no history of prior perineal trauma and with a PSV lower than 35 mL/s should undergo exercise testing before receiving treatment of ED because these patients had a 42% risk of having ischemic heart disease. However, other investigators questioned the utility of using penile arterial flow to predict the presence of ischemic heart disease.18x18Chiu, AW, Chen, KK, Chen, MT, Chang, LS, and Chang, MS. Penile brachial index in impotent patients with coronary artery disease. Eur Urol. 1991; 19: 213–216
Abstract | Full Text | Full Text PDF | PubMed | Scopus (30) | Google ScholarSee all References Erections result from relaxation of the corpora cavernosa, which is mediated either by increasing intracellular cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate or by inhibition of their degradation. Increased parasympathetic tone results in a decrease in norepinephrine release and an increase in the release of acetylcholine; subsequently, NO synthase activity increases, which releases NO from both endothelial cells and nonadrenergic, noncholinergic neurons.10x10Kloner, RA and Zusman, RM. Cardiovascular effects of sildenafil citrate and recommendations for its use. Am J Cardiol. 1999; 84: 11N–17N
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Most of the time, ED is the first symptom of poor cardiovascular health. Hypertension oftentimes doesn’t manifest outward symptoms of heart disease. Some men go undiagnosed with high blood pressure for a long time. It can be troublesome for many men who feel uncomfortable discussing ED with their health providers. Many fail to seek medical advice and suffer from progressive worsening of their cardiovascular problems before deciding to undergo treatment.
Feeling fatigued, very stressed, depressed or dealing with another mood-related issue that can lower libido. Sources of stress and diminished quality of life — such as “deteriorating economic position,” unhappiness with one’s job or other aspects that lower emotional health — are believed to be major causes for sexual dysfunction in both men and women
Medicines known as PDE5 inhibitors can help two-thirds of men with ED. These include Viagra (sildenafil), Cialis (tadalafil) and Levitra (vardenafil). You may need to take several doses over time before they work properly, and you may need to adjust the dose. National guidelines say you can be prescribed these drugs from six months after a heart attack, providing your condition is stable.
The initial event for normal erectile function is sexual stimulation. Subsequent to processing in the central nervous system neural impulses are conveyed along the spinal cord, exiting through the pelvic parasympathetic preganglionic nerves. These pelvic nerves form the pelvic plexus and send their message through first messenger, acetyl choline, to the cavernosal nerves. The cavernosal nerves enter erectile bodies (corpora cavernosa) (Figure 1). Here, their nerve endings release a second messenger, nitric oxide. Nitric oxide activates the enzyme guanylyl cyclase, which lyses guanosine triphosphate (GTP) to produce a third messenger, the intracellular cyclic guanosine monophosphate (cGMP). Ultimately, the result is a decrease of intracellular calcium and an opening of potassium channels with the resultant relaxation of vascular smooth muscle in the arteries, aterioles, and sinusoids of the corpora cavernosa. The sinusoids open and rapidly fill with blood. Finally, the distended sinusoids compress their drainage pathways (venules) against the fibroelastic covering of the cavernosal bodies (tunica albuginea) and trap the blood in cavernosal bodies. The combination of an increased inflow of blood into the penis and coincident markedly diminished outflow results in rapidly increasing intracavernosal pressure that ultimately approximates systolic pressure. At this pressure the penis has sufficient axial rigidity to permit vaginal penetration.
Few simple laboratory tests can help identify obvious causes of organic ED. Initial labs should include HbA1c, free testosterone, thyroid function tests, and prolactin levels. However, patients who do not respond to pharmacological therapy or who may be candidates for surgical treatment may require more in-depth testing, including nocturnal penile tumescence testing, duplex Doppler imaging, somatosensory evoked potentials, or pudendal artery angiography.
Obesity is a strong predictor of ED as it is associated with other risk factors, such as diabetes, hyperlipidaemia and hypertension.4 Obesity increases the risk of ED by 30–90 % and acts as an independent risk factor for CVD. Obese men with ED have greater impairment in endothelial function than non-obese men with ED.5 Moreover, high BMI causes low testosterone levels, which in turn leads to ED, as observed in a prospective trial involving 7,446 participants.50
Abstract | Full Text | Full Text PDF | PubMed | Scopus (395) | Google ScholarSee all References The maximum decrease in blood pressure level was noted at 1 hour after the oral dose was taken and was correlated with peak plasma levels. The blood pressure level in these patients returned to baseline within 4 hours.56x56Wallis, RM, Corbin, JD, Francis, SH, and Ellis, P. Tissue distribution of phosphodiesterase families and the effects of sildenafil on tissue cyclic nucleotides, platelet function, and the contractile responses of trabeculae carneae and aortic rings in vitro. Am J Cardiol. 1999; 83: 3C–12C
Due to their vasorelaxing effect, administration of PDE-5 inhibitors in hypertensive individuals was initially confronted with great suspicion. A wealth of clinical data however has proven that PDE-5 inhibitors are associated with few side effects and provoke a small and insignificant reduction in blood pressure with minimal heart rate alterations in both normotensive and hypertensive patients as well. As a matter of fact, they can be safely and effectively administered to hypertensive individuals even when they are already taking multiple antihypertensive agents[51-56]. The sole exception to the rule is co-administration with organic nitrates, which is an absolute contraindication due to profound and possibly hazardous hypotension effect[57,58]. Moreover, precaution should be taken when PDE-5 inhibitors are combined with a-blockers where, due to possible orthostatic hypotension effect, lower starting doses should be implemented in the therapeutic regime[59-62].
Surgery for erectile dysfunction is usually considered only after all other options have failed. The two surgical options include the insertion of a semi-rigid rod or the implantation of a three-piece inflatable prosthesis. Penile prosthesis implantation has low infection, complication, and malfunction rates. However, since placement of an implant requires permanent injury to the erectile tissue of the penis, implant treatment is considered irreversible.