Julio J. Ferrer-Hita

Cardiogenic shock after primary percutaneous coronary intervention: Effects of levosimendan compared with dobutamine on haemodynamics

Levosimendan is a new calcium sensitizer with positive inotropic properties. Cardiac power output (CPO) has been shown to be instrumental in the diagnosis of cardiogenic shock (CS) and is an important determinant of outcomes.

Utility of Levosimendan, a New Calcium Sensitizing Agent, in the Treatment of Cardiogenic Shock Due to Myocardial Stunning in Patients With ST-Elevation Myocardial Infarction: A Series of Cases

T degree of necrosis produced by ST-elevation myocardial infarction (STEMI) prior to coronary reperfusion, together with a variable amount of myocardial stunning, may have important prognostic repercussions. When both concur, they may give rise to a state of shock and heart failure requiring adequate treatment, classically aimed at increasing contractility (with inotropic drugs), reducing preload and postload (with vasodilating drugs), and attempting to control the cardiac remodeling process (with beta-blockers and angiotensin-converting enzyme inhibitors). The intravenous inotropic drugs currently available (amines and phosphodiesterase inhibitors) improve contractility by increasing intracellular concentrations of free calcium, but they may have potentially deleterious effects by increasing myocardial energy consumption and underlying ischemia and may even produce myocardial necrosis, cardiotoxicity, and arrhythmia. Levosimendan belongs to a new group of inotropic agents developed for cardiovascular therapy: those that enhance the sensitivity of myofilaments to calcium. This drug has positive inotropic and vasodilatory properties, as well as cardioprotective effects, which makes it particularly interesting and beneficial in this clinical context. This is especially so when complicated by cardiogenic shock (CS) due to severe left ventricular dysfunction. We sought to evaluate the acute hemodynamic effects of levosimendan in patients with STEMI revascularized by primary percutaneous coronary intervention (PCI), who subsequently presented CS secondary to severe left ventricular systolic dysfunction.

Spontaneous coronary dissection and cardiogenic shock requiring mechanical circulatory support in a non-transplant center

a Acute and Intensive Cardiac Care Unit, Complejo Hospitalario Universitario de Canarias, Tenerife, Spain b Cardiac Surgery Department, Complejo Hospitalario Universitario de Canarias, Tenerife, Spain c Heart Failure and Heart Transplant Unit, Hospital Universitario 12 de Octubre, – Madrid, Spain d Intensive Care Unit, Hospital Universitario 12 de Octubre, – Madrid, Spain e Interventional Cardiology Unit, Complejo Hospitalario Universitario de Canarias, Tenerife, Spain

Syncopes in a Patient With a History of Radiotherapy: The Importance of a Comprehensive Assessment of Cardiac Involvement. Response

We have read with great interest the case reported by JorgePérez et al concerning a 44-year-old man with a history of thoracic radiotherapy who presented with episodes of exertional syncope. Given the prolonged survival of patients with Hodgkin’s lymphoma and the high radiation doses administered years ago, an increasing number of patients with these characteristics are being referred to cardiology departments. Thus, we consider the case to be of great relevance. During an exercise echocardiogram, the patient experienced an episode that the authors describe, both in the text and the figure legend, as a ‘‘12-second episode of atrioventricular dissociation’’. This is an inaccurate description of the electrocardiogram since, far from independent atrial and ventricular rhythms, what the recording shows is asystole due to the development of complete atrioventricular block. The clinical picture is interpreted as a paroxysmal atrioventricular block secondary to fibrosis of the conduction system as a consequence of the radiotherapy. However, we consider that, in this case, it would have been advisable to carry out an exhaustive study to rule out the presence of coronary artery disease. The effect of radiotherapy on the heart has been dealt with extensively and can take many forms: myocardial, coronary, valvular, pericardial, and conduction system involvement. Coronary artery disease is the most common cardiac condition, occurring in up to 8.4% of patients who undergo thoracic radiotherapy, according to the reported series. The histological findings include interstitial fibrosis and luminal narrowing secondary to intimal proliferation, with a predilection for the coronary artery ostia because of the anterior position of the origin of the 2 coronary arteries in the thoracic aorta. In the case reported by Jorge-Pérez et al, this possibility is even more probable because of the severe calcification the mitral and aortic valves and the subvalvular aortic calcification revealed by the echocardiogram. As has been reported previously, paroxysmal atrioventricular block may be of ischemic origin, which in most published cases corresponds to a disturbance of the His-Purkinje system conduction. In the patient discussed herein, the involvement of the HisPurkinje system is evident, not only because of the presence of right bundle branch block in the baseline electrocardiogram, but also because of the 65 ms-HV interval measured in the electrophysiological study. In this respect, it is also necessary to point out that the HV interval is by no means ‘‘within normal limits’’, as the authors report, given that this limit has been set at 55 ms (up to 60 ms can be accepted in patients with left bundle branch block). Atrioventricular block secondary to radiotherapy-induced coronary artery stenosis has been described in previous studies, and the consequences can be serious unless revascularization is undertaken (particularly in this patient because of his profession as a truck driver). Thus, we consider that, in this case of exerciseinduced atrioventricular block in the His-Purkinje system, coronary angiography should have been performed to rule out an ischemic cause, before attributing it exclusively to the direct effects of the radiotherapy on the conduction system.

Radiotherapy-induced Recurrent Syncope

Cardiac toxicity secondary to radiotherapy has an incidence of 10% to 30%. This complication usually develops 5 to 10 years after the administration of the therapy and has been related both to the location of the radiation in the thoracic region and to the dose used (generally over 40 Gy). Radiotherapy-induced cardiac toxicity can lead to ischemic heart disease, different degrees of valve involvement, hypertensive heart disease, ventricular dysfunction, or changes in the intrinsic conduction system. The major causal mechanism is the fibrosis developed by the patients, which can first be detected up to 20 to 25 years after therapy was received. We present the case of a 44-year-old man with no cardiovascular risk factors, who had undergone radiotherapy and chemotherapy 20 years earlier to treat Hodgkin’s lymphoma. He attended the emergency department after experiencing 2 episodes of exertional syncope. The initial electrocardiogram revealed complete right bundle branch block, a previously diagnosed condition (Figure 1) for which the patient had undergone cardiac evaluation a few years earlier, including transthoracic echocardiography which revealed left ventricular hypertrophy. During the first 24 hours of electrocardiographic monitoring, there were no changes in heart rhythm or arrhythmic events of interest. The transthoracic electrocardiogram revealed severe mitral and aortic valve calcification, with mild aortic stenosis and moderate regurgitation. We also observed a small subvalvular aortic calcification near the anterior mitral leaflet, which did not produce an important resting gradient (videos 1-3 of the supplementary material). As the syncope had occurred more than once and had been induced on both occasions by mild exertion, and given the risk associated with the patient’s occupation (truck driver), an in-depth study was carried out. The responses to carotid sinus massage and tilt table test were negative. The electrophysiological study revealed an AH interval of 108 ms, an HV interval of 65 ms, and a supra-Hisian Wenckebach period of 410 ms, all within normal limits, whereas the responses to atropine and procainamide were negative. As there was a dynamic obstruction in the left ventricular outflow tract related to the subaortic calcification, exercise echocardiography was performed in an attempt to reproduce the symptoms. In the third minute of the test, the patient developed atrioventricular dissociation with a 12-second pause (Figure 2), followed by a syncopal episode, with subsequent spontaneous recovery. The next day, he underwent implantation of a permanent dual-chamber pacemaker. The long-term survival associated with Hodgkin’s lymphoma due to the good response generally achieved with radiotherapy and chemotherapy, and the high radiation doses administered in the thoracic region 20 years earlier, were important factors in the development of cardiac toxicity over the long-term. We have no information on the chemotherapy regimen received by our patient, as it was administered at another center. The progressive myocardial fibrosis generated by the radiotherapy leads to cardiac manifestations; among these, involvement of the conduction system is one of the least frequent, compared with cardiac valve involvement, ischemic heart disease, or left ventricular systolic dysfunction, which are the most common reasons for patients with this profile to seek medical attention. The follow-up of asymptomatic patients has not been clearly established, but symptoms such as angina or dyspnea should point to radiotherapy as a possible cause in those who have undergone this treatment in the past. Our patient had been evaluated 5 years prior to hospital admission due to the presence of asymptomatic right bundle branch block. This block is an incidental finding resulting from conduction system involvement and is generally more common