Vol 1, No 1 sup (2006) - Cardiology Update 2006
Kostas G. Kappos, Vassiliki Tsagou, Antonis S. Manolis
The right ventricular (RV) apex has been used as the traditional pacing site since the development of transvenous pacing in 1959. Some studies suggest that pacing the RV apex may cause an "iatrogenic" left bundle branch block and remodeling of the left ventricle and is therefore harmful. In the past decade, the need for alternate site pacing became imperative and there have been a multitude of studies of the hemodynamic, electrophysiological, electrocardiographic, and clinical effects of ventricular pacing at other sites.Pacing of the left ventricle singly or with biventricular pacing has emerged as an effective and safe therapy for moderate to severe congestive heart failure in patients with prolonged QRS complexes. Studies of alternate RV sites, like the RV outflow tract, have given mixed results, and further clarification of the specificsites of the RV outflow tract is needed. Direct His-bundle pacing is an attractive alternate pacing site because of the possible hemodynamic benefits that could be obtained by a normal activation sequence, but the small size and anatomic position of the His bundle have made this approach difficult. Bifocal RV resynchronization therapies have been used as an alternative to biventricular pacing. Περισσότερα
Vol 1, No 1 sup (2006) - Cardiology Update 2006
Konstantinos G. Kappos, Vassiliki Tsagou, George Andrikopoulos, Spyros Koulouris, Stylianos Tzeis, Chryssanthi Dasopoulou, John Pyrros, Athanasios Kranidis,
Antonis S. Manolis
Foramen ovale plays a very important role in fetal circulation by bypassing the lungs and diverting circulation from the right to the left heart. With birth it is usually sealed; however, probe patent or incompletely sealed foramen ovale remains in approximately 25% of adults. Patent foramen ovale (PFO) acquires significance in various congenital heart diseases or other particular settings leading to a right to left shunt, and thus to paradoxical embolism. PFO has been associated with transient ischemic attacks or cryptogenic strokes and also a host of other problems, including migraine. The recognition of an association between migraine syndrome with aura and PFO appears to have come "full circle" over the past two decades. Epidemiologic studies have suggested a notably increased PFO prevalence in persons suffering from migraine.The prevalence of migraine headache is higher in cryptogenic stroke patients with PFO than in the general population. Studies have suggested that closure of the PFO may reduce migrainous symptoms. The relation between this association and the recognition of migraine as a risk factor for ischemic stroke in the young is unclear, though right to left passage of circulating factors has been postulated in both syndromes. Despite case series and uncontrolled studies documenting beneficial effects of PFO closure in patients with migraine, particularly those also afflicted by cryptogenic stroke, the recommendation for PFO closure in patients with migraine alone will need to await the results of ongoing randomized trials. Περισσότερα
Clinical Cardiology, 29, no. 8 (2006): 369-371
Antonis S. Manolis, George Andrikopoulos, Vassiliki Tsagou, John Pyrros,
Summary: A 43-year-old woman was undergoing radiofre- quency catheter ablation of a symptomatic supraventricular tachycardia when a patent foramen ovale (PFO) was detected with passage of the diagnostic electrocatheter into the left atrium. Prior echocardiographic studies had been unreveal- ing. Upon questioning during the procedure, the patient now admitted to frequent and disabling daily migraine attacks, while her family described two recent brief episodes of dis- orientation and dysarthria, consistent with transient ischemic attacks. The patient was informed of the option of future clo- sure of the PFO, but she insisted on having this done concur- rently with her ablation procedure. After successful ablation of the slow pathway considered responsible for the supraven- tricular tachycardia, an Amplatzer closure device was util- ized and the PFO was successfully closed during the same procedure. A postprocedural transesophageal echocardio- gram showed complete sealing of the PFO, while over the en- suing 10 months the patient reported virtual elimination of her daily attacks of migrainous headaches, limited to a single episode the day after the procedure and none thereafter. Περισσότερα
Vol 6, No 4 (2011) - Reviews
Chrysanthi Dasopoulou, Sofia Metaxa, Vassiliki Tsagou, John Michaelides, Spyridon Koulouris, Antonis S Manolis
Sleep disordered breathing is a rather common problem in the general population. Apnea during sleep can be divided into three types: central, obstructive and mixed. In central apneas there is lack of both airflow and respiratory efforts. It is recognized by its waxing-waning pattern of respiration called Cheyne- Stokes respiration. Central sleep apnea is most commonly seen in patients with heart failure and its prevalence among this group of patients is estimated to be as high as 30-40%. Obstructive sleep apnea occurs approximately in 5-15% of the general population. It usually affects middle-aged men with an increased body-mass index and a large neck circumference. It is characterized by repetitive complete or partial obstruction of the upper airway during sleep, which is followed by increasing and ineffective respiratory efforts.
Sleep fragmentation in patients with sleep apnea syndrome results in sleepiness, fatigue, morning headaches and depression. This daytime presentation together with loud snoring, choking and pauses of respiration during sleep should make primary care physicians suspicious of sleep disordered breathing. The best method used for the diagnosis of sleep apnea syndrome is overnight polysomnography.
The pathophysiologic mechanisms, which take place in sleep apnea, include sympathetic activation, hypercoagulability, inflammation and production of pro-inflammatory cytokines, endothelial dysfunction, oxidative stress and metabolic dysfunction. All these mechanisms are associated with the development and progression of cardiovascular disease. There is a strong linkage between sleep apnea and hypertension, systolic and diastolic dysfunction of the left ventricle, congestive heart failure, coronary artery disease, cardiac arrhythmias, stroke and pulmonary disease.
Given the increased morbidity and mortality of patients with sleep apnea, an effective treatment must be started as soon as possible after the diagnosis is made. Currently, nasal continuous positive airway pressure constitutes first line therapy. This therapy improves both quality of sleep and cardiovascular and general outcomes.