Diabetes und Herz

Background

Diabetes remains a leading risk factor for cardiovascular events.

Current diabetes therapies

For the therapy of type 2 diabetes mellitus metformin is available as the first choice treatment. The decision which anti-diabetic drug should be used for second line therapy is left up to the treating physician. The decision-making process is largely influenced by the results of new cardiovascular outcome trials, which are carried for newly introduced diabetes medications.

Diabetes therapy and cardiovascular risk

Outcome studies for three classes of drugs were presented in the previous year, which are discussed in this article. Furthermore, this article presents recent advances in the possibilities for coronary interventions in patients with diabetes and mechanisms of diabetic cardiomyopathy are discussed.

     

Sepsis und Herz

In patients suffering from severe sepsis an impairment of cardiac function is seen constantly. Patients with septic shock often show a transient reduction of cardiac ejection fraction. Besides, a tremendous impairment of heart rate variability corresponding to a poor prognosis is often found. Endotoxin might play a pivotal role in the conjunction of inflammation and the disturbance of heart rate regulation. Experimental studies show that the complex interactions of endotoxin, the cardiac pacemaker current I _f, and the autonomous nervous system lead to an increase of resting heart rate and in parallel to a decrease of heart rate variability – as typically seen in patients with severe sepsis. The method of choice to quantify the degree of septic cardiomyopathy at the intensive care unit certainly is to determine cardiac output in relation to systemic vascular resistance. Unfortunately, clinical trials aiming to influence the causal pathogenesis of septic cardiomyopathy (inhibition of excess formation of nitric oxide, suppression of cytokine release etc.) were rather disappointing so far. Positive effects might be assumed for the administration of activated protein C thereby underlining the role of microcirculatory alterations in the development of septic cardiomyopathy.     

Herz und Niere

There is strong interaction between heart and kidneys in human beings. Both organs work together in many regulation mechanisms. Thus, heart failure lead in many cases to renal failure due to hemodynamic or hormonal feed-back mechanisms. Vice versa, chronic kidney disease turned out as a major and independent cardiovascular risk factor. Patients who suffer from both heart disease and chronic kidney disease are threatened from a very high morbidity and mortality. Moreover, the number of affected patients has doubled every 8–10 years – a dramatic trend which is ongoing. In many patients suffering from heart and chronic kidney disease, an under-use of cardiologic diagnostics as well as therapies has to be observed due to fears about adverse effects, which further enhances their worse prognosis.     

Herz und Niere

Arterial hypertension is a major cardiovascular risk factor with a high prevalence in western industrial countries and the proportion of patients with blood pressure at target values remains low. Patients with therapy-resistant hypertension, defined as failure to achieve target blood pressure despite a triple antihypertensive drug regimen including a diuretic, are at very high risk which supports the need for greater efforts towards improving hypertension outcomes in this population. Secondary causes of hypertension are often found in patients with resistant hypertension. Activation of the sympathetic nervous system has been identified as a main contributor to the development and progression of high blood pressure. Catheter-based renal denervation offers a new interventional treatment option resulting in a significant long-term reduction in blood pressure (>?36 months) and increased blood pressure control (up to 40% of the treated population). The basis for successful treatment is an appropriate patient selection, including life-style modification, exclusion of pseudoresistance, termination of substances increasing blood pressure and an optimized drug treatment. Further clinical studies are warranted and ongoing to determine the role of renal denervation in antihypertensive treatment.     

Herz und Sport

Ohne Zusammenfassung     

Hochdruck und Herz

Arterial hypertension often leads to diseases of kidneys, vessels and brain. Besides these end organ damages the changes of the heart are of important role. Substantial consequences of hypertension are microangiopathy, interstitial fibrosis and left ventricular hypertrophy. Hence, as an early stage diastolic dysfunction results. Due to longer persistent hypertension also systolic dysfunction develops. Clinically, patients suffer from angina pectoris, dyspnoea and cardiac arrhythmias (i.e. atrial arrhythmia, atrial fibrillation). The left ventricular hypertrophy also is associated with an increased risk of malignant ventricular arrhythmias. The risk of sudden cardiac death is raised as well, in particular in patients with dilated heart and reduced left ventricular ejection fraction. Well controlled antihypertensive therapy could lead to a regression of left ventricular hypertrophy. Hence, disorders and prognosis of the patients could be improved.     

Herz und Lunge

Dyspnea is one of the major clinical symptoms which patients report to general practitioners, internists, cardiologists and hospitals. In this review article we discuss the evidence of medical history, laboratory procedures and diagnostic investigations to approach patients with acute or chronic dyspnea and try to structure this complex symptom dyspnea to reach the etiology of the underlying disease.     

Alkohol und Herz

The cultural and natural scientific ambivalence of the heart and alcohol has long been the subject of philosophical, artistic, intellectual and emotional discussions, not uncommonly in a romanticizing manner. The indulgence of alcoholic beverages in moderation is contrasted by the inestimable risks and dangers of alcohol abuse with many cardiovascular implications, such as cardiac arrhythmia, cardiomyopathy and arterial hypertension. The inspirational mental effects of alcohol have been emphasized in many citations from Classical Antiquity through the Middle Ages and even in modern times. In addition to wine and beer many alcoholic drinks, such as Champagne, sparkling wines, whisky (or whiskey), brandy (Cognac) and fruit brandies have a nearly ritual culture of traditions and customs, without which social life would be unthinkable. The interplay between enjoyment and displeasure is emphasized in the year 2016 with the 500-year jubilee of the German purity requirements for beer with countless events, including the Bavarian State Exhibition 2016. Recently, evidence of a neuroprotective effect of alcohol was reported with an improvement of intellectual capacity, which could counteract the widely occurring dementia syndrome. Millions of people could profit from this effect.     

Herz und Niere

The cardiorenal syndrome (CRS) is seen in increasing numbers in emergency rooms, intensive care units, hospitals as a whole and outpatient departments. This is caused by the demographic shifts that lead to increasing numbers of elderly patients with multimorbidities. Often a heart disease is causing kidney failure and vice versa. The management of these patients is difficult due to the fact that often the goals of therapy are opposite. Patients with chronic kidney disease (CKD) have a 100-fold increased risk for the development of cardiovascular diseases (CVD). CKD alone is an important cardiovascular risk factor and has surpassed diabetes mellitus as a risk factor by far. However, awareness of this is low among doctors and patients. The treatment of patients with CRS is different from patients with CVD alone. The goals of therapy are different and the findings of studies in patients with CVD without CKD cannot simply be extended to these patients.     

Tauchen und Herz

Diving with self-contained underwater breathing apparatus (scuba) has become a popular recreational sports activity throughout the world. A high prevalence of cardiovascular disorders among the population makes it therefore likely that subjects suffering from cardiovascular problems may want to start scuba diving. Although scuba diving is not a competitive sport requiring athletic health conditions, a certain medical fitness is recommended because of the physical peculiarities of the underwater environment. Immersion alone will increase cardiac preload by central blood pooling with a rise in both cardiac output and blood pressure, counteracted by increased diuresis. Exposure to cold and increased oxygen partial pressure during scuba diving will additionally increase afterload by vasoconstrictive effects and may exert bradyarryhthmias in combination with breath-holds. Volumes of gas-filled body cavities will be affected by changing pressure (Figure 1), and inert gas components of the breathing gas mixture such as nitrogen in case of air breathing will dissolve in body tissues and venous blood with increasing alveolar inert gas pressure. During decompression a free gas phase may form in supersaturated tissues, resulting in the generation of inert gas microbubbles that are eliminated by the venous return to the lungs under normal circumstances. Certain cardiovascular conditions may have an impact on these physiological changes and pose the subject at risk of suffering adverse events from scuba diving. Arterial hypertension may be aggravated by underwater exercise and immersion. Symptomatic coronary artery disease and symptomatic heart rhythm disorders preclude diving. The occurrence of ventricular extrasystoles according to Lown classes I and II, and the presence of atrial fibrillation are considered relative contraindications in the absence of an aggravation following exercise. Asymptomatic subjects with Wolff-Parkinson-White syndrome may be allowed to dive, but in case of paroxysmal supraventricular tachycardia they must refrain from diving. Pacemakers will fail with increasing pressure, but some manufacturers have proven their products safe for pressure equivalents of up to 30 m of seawater, so that patients may dive uneventfully when staying within the 0-20 m depth range. Significant aortic or mitral valve stenosis will preclude diving, whereas regurgitation only will not be a problem. Right-to-left shunts have increasingly gained attention in diving medicine, since they may allow venous gas microbubbles to spill over to the arterial side of the circulation enabling the possibility of arterial gas embolism. Significant shunts thus preclude diving. The highly prevalent patent foramen ovale is considered a relative contraindication only when following certain recommendations for safe diving (Table 2). Metabolic disorders are of concern, since adiposity is associated with both, higher bubble grades in Doppler ultrasound detection after scuba dives when compared to normal subjects, and an increased epidemiologic risk of suffering from decompression illness. In conclusion, cardiovascular aspects are important in the assessment of fitness to dive, and certain cardiovascular conditions preclude scuba diving. Any history of cardiac disease or abnormalities detected during the routine medical examination should prompt to further evaluation and specialist referral.