Local thrombolysis for deep vein thrombosis: why, for whom and how?

Despite the progress achieved in prevention and therapy in recent decades, venous thromboembolic disorder still presents medical burden. Incidence is estimated about 100-200/100 000 per year. Patients, who underwent deep vein thrombosis are at risk of recurrence and/or development of post-thrombotic syndrome. Both can affect the quality of life. In acute phase of the disease anticoagulation and compression are effective therapy in most cases. But in severe clinical manifestations escalation of the therapy should be considered. Surgical embolectomy is possible, but complication rate is high. Endovascular approaches are viable option. Catheter directed local thrombolysis is effective not only in situation of limb emergency (phlegmasia). We summarize indications, technical approach and evidence for this specific treatment.

Clinical characteristics of 30 Czech families with long QT syndrome and KCNQ1 and KCNH2 gene mutations: importance of exercise testing.

BACKGROUND: Classic symptoms of long QT syndrome (LQTS) include prolongation of QT interval on electrocardiograph, syncope, and cardiac arrest due to a distinctive form of polymorphic ventricular tachycardia, known as Torsade de Pointes. We assessed occurrence of LQTS signs in individuals from 30 Czech families with mutations in KCNQ1 and KCNH2 genes. METHODS AND RESULTS: One hundred five individuals from 30 Czech families with LQTS were genotyped for KCNQ1 and KCNH2. The occurrence of typical LQTS signs (pathologic prolongation of QT interval; syncope; cardiac arrest; Torsade de Pointes) was clinically assessed by exercise test with QT interval analysis. Family history of sudden cardiac death was taken. Statistical analysis was performed to determine correlation of clinical results and mutation status. KCNQ1 gene mutations were found in 23 families, and KCNH2 gene mutations in eight families. Only 46 (70%) of the 66 mutation carriers had at least two of the typical LQTS signs. The others were minimally or asymptomatic. From 39 noncarrier individuals, only 1 fulfilled the clinical criteria of LQTS diagnosis, another 4 had an intermediate probability of diagnosis. The exercise test had 92% sensitivity and 93% specificity for LQTS diagnosis. CONCLUSIONS: Incidence of classical signs of LQTS was not high in Czech carriers of KCNQ1 and KCNH2 mutations. Therefore, proper diagnosis relies on detection of symptoms at presentation. The exercise test may be beneficial owing to its high sensitivity and specificity for LQTS diagnosis.

Mutation analysis ion channel genes ventricular fibrillation survivors with coronary artery disease.

BACKGROUND: Observations from population-based studies demonstrated a strong genetic component of sudden cardiac death. The aim of this study was to test the hypothesis that ion channel genes mutations are more common in ventricular fibrillation (VF) survivors with coronary artery disease (CAD) compared to controls. METHODS: The entire coding sequence of KCNQ1, KCNH2, SCN5A, KCNE1, and KCNE2 genes was analyzed in 45 (five females) CAD individuals-survivors of documented VF and in 90 matched healthy controls. In another control group of 141 matched patients with CAD without malignant arrhythmias, the exons containing rare coding variants found in the VF survivors were sequenced. RESULTS: The carrier frequency of all the rare sequence variants was significantly higher in the VF survivors (8/45, 17.8%) than in CAD controls (3/141, 2.2%, P = 0.001). In VF survivors, four coding variants in eight individuals were found. Three in KCNH2 gene: R148W and GAG186del are novel; P347S was previously related to long QT syndrome. In SCN5A gene, P2006A variant was found in five unrelated males. This variant has been demonstrated previously to have small effect on sodium channel kinetics. No rare coding variants were found in the healthy controls. The P2006A variant was found in three CAD controls. CONCLUSION: The prevalence of selected, rare coding variants in five long QT genes was significantly higher in cases versus controls, confirming a mechanistic role for these genes among a subgroup of patients with coronary disease and VF.

Monitoring of QT interval in patients treated with psychotropic drugs.

BACKGROUND: Psychotropic drugs have the potential for QT interval prolongation, the frequency is not known. The aim of this study was to monitor the occurrence of QT interval prolongation in a non-selected population of patients treated with psychotropic drugs with proarrhythmic potential. METHODS: In consecutive patients hospitalized at psychotic wards at the Department of Psychiatry treated with antipsychotic and antidepressant drugs with known or unexplored proarrhythmic potential a 12-lead ECG was recorded (50 mm/s, 20 mm/mV) on therapy; the QT interval was measured manually, corrected according to Bazett and Fridericia. QTc intervals of 470 ms (females) and 450 ms (males) were considered borderline, longer QTc intervals were considered pathologic. RESULTS: ECGs were recorded in 452 patients (187 females, 265 males, aged 43+/-16 years). Using Bazett's correction, abnormal QTc values were observed only in 2% of the whole group and in 1.8% of the patients treated with drugs associated with QT prolongation (the greatest QTc value is 490 ms in female and 480 ms in male). With Fridericia's correction, there was only 1 case of borderline QTc in the whole group (the greatest QTc value is 450 ms in both sex groups). CONCLUSIONS: Our 2-year real-life experience shows that occurrence of QTc prolongation in present psychiatric patients is low. Values associated with high risk of arrhythmias (QTc>500 ms) were not observed. This might be related to the recent changes of spectrum of antipsychotic therapy used, the general trend to use lower doses, and increasing awareness about the drug-induced long QT syndrome.

The homozygous KCNQ1 gene mutation associated with recessive Romano-Ward syndrome.

In a 7-year-old boy with normal hearing suffering from repeated syncope an extremely prolonged QTc interval (up to 700 ms) was found. The mother was completely asymptomatic and the father had an intermittently borderline QTc interval (maximum 470 ms) but no symptoms. In the proband a mutation analysis of KCNQ1 gene revealed a homozygous 1893insC mutation. The parents were heterozygous for this mutation. There was no consanguineous marriage in the family. The clinical relevance of these findings is that apparently normal individuals may have a latent reduction of repolarizing currents, a "reduced repolarization reserve," because they are carriers of latent ion channel genes mutations.

Occurrence of notched T wave in healthy family members with the long QT interval syndrome.

The notched T wave is considered 1 of the diagnostic signs of long QT interval syndrome (LQTIS). The investigators report observations of notched T waves in noncarrier members of families with LQTIS and compare the exercise-induced dynamic behavior of these complex T-wave patterns in mutation carriers and noncarriers of 3 families with LQTIS.